The present invention relates to an ACME centralized management system and a load balancing method thereof. The system is connected with an ACME client and a plurality of certificate authorities (CAs) respectively and comprises an ACME unloading module, and a statistics module, a strategy module, a verification module and a notification module which are connected with the ACME unloading module respectively. The ACME unloading module is in communication with the ACME client and the plurality of certificate authorities (CAs). Compared with the prior art, the present invention has the advantages of avoiding frequent verification, quickly issuing certificate copies, more efficiently issuing certificates, etc.