Chips are tested before electrical installation, which is an important precondition to ensure the reliability and stability of systems. A test method of M128-554 communications processor module produced in domestic is introduced. The characteristics of the module are analyzed. An automatic testing platform which includes a PC controlling center, a tested module M128-554, a microcontroller CPU TM128 with 4 serial ports simulation signal and two 16C554 chips with 4 serial ports communication capability is built. Combined with C51 language and Borland C++ builder6.0 language, design and implementation of the test system are completed. The detailed design schemes and testing methods are described.