The invention discloses a test instrument sharing usage method and a test system in an automatic optical module test. The system comprises a plurality of testing machine platforms, optical modules to be tested, optical module testing instruments, servers, switchboards and optical switches, wherein the testing machine platforms are connected with the switchboards, the switchboards are connected with the servers, the servers are connected with all the optical module testing instruments, and the optical module testing instruments are with the optical modules to be tested which are arranged on the testing machine platforms through the optical switches. Control is achieved through servers, when a testing machine platform requires an optical module testing instrument, the testing machine platform applies for resources of the instrument for a server, when the instrument idles, the server distributes the resources of the instrument to the testing machine platform, at the same time, the instrument is remarked to be occupied until the testing machine platform releases the usage of the platform, and if one instrument is occupied by one of the testing machine platforms , the other testing machine platform can apply for the usage of other instruments. According to the method and the system, by the aid of the server, testing resources are coordinated, a plurality of optical modules can be detected, and the utilization rate of the instruments can be improved.