With the popularization of multimedia technology in the application on teaching, the actual application on teaching software has become a major problem that computer-assisted instruction (CAI) in-depth developed. Constructing a scientific, objective, and fair evaluation system of multimedia teaching software has become imperative. By combining current characteristics of CAI and various evaluating indicator at home and abroad , a more reasonable evaluation system is proposed in this paper. Experimental data show that the evaluation system is feasible and effective, and has a wide range of applications.