In order to comprehensively evaluate the applicability of plant protection machinery, this paper established the evaluation index system from three aspects：technical index, economic index and operation condition index, used analytic hierarchy process to calculate the results of the expert questionnaires based on the structure model of the evaluation system, and determined the weights of each evaluation index by using judgment matrix and weighted geometric average method. And then it obtained the scores of the third level indicators by the method of test, as well as survey and evaluation of users, and then got the index scores of all levels through analysis and calculation. Finally the comprehensive evaluation index system for the applicability of plant protection machinery was built. This paper evaluated the selfpropelled boom sprayer for example, and obtained the conclusions of the single index evaluation and the comprehensive evaluation. This can provide scientific basis for popularization and application of plant protection machinery by the comprehensive evaluation system, at the same time, it has guiding significance to the optimization and promotion of mechanical performance and operations quality of plant protection machinery.