Army composite operational unit is the smallest tactical unit for systematic combat operations. The assessment and analysis of its combat efficiency are urgent issues to be addressed in military studies. This article focuses on the application of data envelopment analysis （DEA） and Malmquist Productivity Index in the evaluation of combat unit's combat efficiency. It constructs the DEA-Malmquist evaluation model for combat units and utilizes the dynamic and concise advantages of the Malmquist index to evaluate the efficiency and dynamic changes of different combat units in multiple combat stages based on input-output data. The analysis， evaluation process， methods， and conclusions of this study can provide valuable references and insights for the construction and utilization of composite operational units and the military application of Malmquist productivity index.