Inclusion Criteria:  Patients in ICU who need to be treated with β-lactam antibiotics for clinical diagnosis of infection; Meet the diagnostic criteria of sepsis 3.0 in the previous 24h; At assessment of eligibility, treating doctor expects patient to need treatment in ICU beyond the next calendar day.  Exclusion Criteria:  The infection is diagnosed clinically, but the acquired pathogens are not sensitive to the study drug; Has a history of allergies to study drugs; Those who have a serious condition and the expected survival time is less than 72 hours. Receipt of potential study medication for > 24 hours before randomization. Pregnancy Death is deemed imminent and inevitable. Receiving palliative or supportive treatment only at the time of assessment for eligibility. Treating doctor not committed to provision of advanced life-support, including any of mechanical ventilation, dialysis and vasopressor administration for at least the next 48 hours. Consent not gained for study participation and entry under a waiver-of-consent not approved by the jurisdictional human research ethics committee.