Budsarakhum Hospital was a large field hospital specialized in providing temporary care for COVID-19 patients, where modern technology was used in providing comprehensive patient care according to referral and treatment standards addressing both physical and mental health. However, there are still few studies in the management system of field hospitals in Thailand. Therefore, it is necessary to study the body of knowledge that leads to the development of a field hospital management system in the face of a crisis other than COVID-19. This is qualitative research. The research objectives were 1) to study the current situation of the field hospital management system in the situation of COVID-19: A Case Study of Budsarakhum Hospital, 2) to study the problems, obstacles, and recommendations for hospital management systems in the Covid-19 Situation: A Case Study of Budsarakhum Hospital, and 3) to synthesize policy recommendations for the development of field hospital management systems. The researcher collected data by in-depth interview during December 2021 - January 2022. The purposive sample composed of 43 participants who were executives in policy level as well as executives from various departments, Budsarakhum Hospital as follows: Director of the Field Hospital under the Department of Medical Services; Director of University Field Hospital; Director of Private Field Hospital; Emergency Medical Specialist; Deputy Director of Budsarakhum Hospital; Secretary of Emergency Medical Department; Executive of Administrative Staff including nurses; Team Leaders of Referral, Loading, Caring, Treatment, Medical Emergency Response Team (MERT); Information Technology staffs; medical practitioners including doctors, nurses, pharmacists, and patients who have been already admitted to Budsarakhum Hospital. Data was collected through a semi-structured interview form developed by the researchers from the literature review and it has been consistent with the objectives. Content validity was checked by experts and to determine the reliability of the tool. The research team collected data from 1) Documents related to the operation of Budsarakhum Hospital, including: documents on the operating policy of Budsarakhum Hospital; hospital structure; processes of those involved, including executives, key and supplemental practitioners in all field hospital zones; as well as documentation related to performance outcomes in the field of COVID-19 patient care; 2) Information systems related to the operation of Budsarakhum Hospital such as news in various media, various announcements, websites, and Facebook related to Budsarakhum Hospital; 3) Sample groups were then analyzed using the content from all the data, in order to categorize and interpret the data according to research objectives as follows: 1. Field hospital management model in the situation of COVID-19 from the review literature and interviews with experts consisted of input factors, including structure, (i.e. location/objectives/hospital structure, setting up working group, team and responsibilities). The process aspect, including commanding/coordinating/control, inside and outside organization communication, emergency mobilization, information technology management, risk management, infection control, and medical record systems. Staff, including recruiting manpower, roles/responsibilities, orientation/training, staffing/scheduling, morale building, compensation and benefits. Supply, including financial management, handling of medical materials/devices. Process factors, including admission/diagnosis, screening clinical care, medical record/document system, continuing care/referral system, and psychological care. Outcome factors, consisting of outcome follow up. The management of Budsarakhum Hospital was consistent when compared to literature review and experts in the management model of field hospitals in the situation of COVID-19, except for emergency mobilization and the outcome follow up. 2. Problems, obstacles, and strategies of the hospital management system in Budsarakhum Hospital were found in various aspects, including hospital structure, communication outside the organization, risk management, infection control, recruitment, medical records system, personnel stress management, handling of medical materials/devices, admission, clinical care, patient referral system, and outcome following up. 3. Policy recommendations for the development of field hospital management systems consisting of staff, system, supply, and structure. Recommendations for Staff include: develop workforce plan of field hospitals in both the central and regional areas; train health care personnel to work in emergency situations; develop a system of volunteering from both the public, private, and public sectors; develop a system to increase health literacy for people to have basic self-care in emergency situations; study and research knowledge gained from field hospital services and develop innovations that support the management system of personnel and patient care in field hospitals; add disasters course to curriculum and practicum of health care students. Recommendations for System include: develop a field hospital practice manual which include inputs, processes, and  outcomes; establish the Public Information Officer; develop a system for monitoring health outcomes and voice of customers (VOCs); develop information technology system in field hospitals; develop cooperative human resource plan among government sectors and between the government and the private sectors. Recommendations for Supply include: establish cooperation policy in sharing medical devices between public and private hospitals in emergency situation; build networks with agencies and communities to participate and support the establishment of field hospitals. Recommendations for Structure include: develop a manual for the field hospital structure which consists of place of establishment, layout of the space, zoning, and command line.