A voice communication interface device for debugging a stable control system comprises a host machine, an extension set and transmission optical fibers and is characterized in that a photoelectric converter in the host machine is connected with a photoelectric converter in the extension set through the transmission optical fibers; in the host machine, a serial communication controller is respectively connected with a field-programmable gate array and a microprocessor, the field-programmable gate array is respectively connected with a voice decoding chip, the photoelectric converter and a communication converter. The voice decoding chip is connected with a microphone and an earphone; in the extension set, the field-programmable gate array is respectively connected with the photoelectric converter, a 2-M interface and a 64K interface. Under the condition that normal data of the regional stable control system and control of information transmission are reliably guaranteed, clear and distortionless voice duplex communication among each station is achieved conveniently. The voice communication interface device for the debugging stable control system is characterized in that a large scale integrated circuit and an integrated light receiving and transmitting device are adopted, so that the system is stable and reliable; a status indicator is complete, so that maintenance and fault processing are convenient.