A centralized control method for a multi-split air conditioning system, comprising: upon acquiring an identification code of an outdoor unit of the multi-split air conditioning system, sending, by a debugging terminal, a first acquisition request to a cloud server on the basis of the identification code, to allow the cloud server to search for system information of the multi-split air conditioning system corresponding to the identification code and send the system information to the debugging terminal; upon receiving the system information sent by the cloud server, creating, by the debugging terminal, a project on the basis of the system information; characterized in that the centralized control method for the multi-split air conditioning system further comprises: after creating the project, uploading, by the debugging terminal, project information corresponding to the project to the cloud server, to allow the cloud server to generate a delivery code corresponding to the project information and to store the delivery code and the project information in association with each other; when a centralized control device corresponding to the multi-split air conditioning system receives the delivery code, sending, by the centralized control device, a second acquisition request to the cloud server on the basis of the delivery code, to allow the cloud server to send the project information corresponding to the delivery code to the centralized control device; and upon receiving the project information, loading, by the centralized control device, the project corresponding to the delivery code on the basis of the project information, and activating the project by the centralized control device. upon acquiring an identification code of an outdoor unit of the multi-split air conditioning system, sending, by a debugging terminal, a first acquisition request to a cloud server on the basis of the identification code, to allow the cloud server to search for system information of the multi-split air conditioning system corresponding to the identification code and send the system information to the debugging terminal; upon receiving the system information sent by the cloud server, creating, by the debugging terminal, a project on the basis of the system information; characterized in that the centralized control method for the multi-split air conditioning system further comprises: after creating the project, uploading, by the debugging terminal, project information corresponding to the project to the cloud server, to allow the cloud server to generate a delivery code corresponding to the project information and to store the delivery code and the project information in association with each other; when a centralized control device corresponding to the multi-split air conditioning system receives the delivery code, sending, by the centralized control device, a second acquisition request to the cloud server on the basis of the delivery code, to allow the cloud server to send the project information corresponding to the delivery code to the centralized control device; and upon receiving the project information, loading, by the centralized control device, the project corresponding to the delivery code on the basis of the project information, and activating the project by the centralized control device.