In order to realize the localization function replacement of control assembly used in the gas turbo-generator set of a certain imported weapon system, a new method is proposed based on reverse engineering method and technology of digital signal processor (DSP). This method is used to uncover the control assembly function and working procedure through cracking display and communication protocol. The result is verified from the aspect of hardware and software. At present, the localized control assembly has been used in a factory and in the army to guarantee equipment maintenance and support, and can meet the gas turbo-generator set’s normal requirement. It surpasses purchased assembly from abroad in systems compatibility.