To overcome the comprehensive evaluation problems for analysis on light and small sprinkler irrigation system, an idea of principal component analysis (PCA) method was presented, and the mathematical model of comprehensive evaluation was established. Five important single technical indexes, which were used for evaluating its technical characteristic, included irrigated area, irrigated depth, uniformity coefficient and energy consumption. Four light and small sprinkler irrigation systems were evaluated by using the composite model. Results showed the former two principal components contained 98.75% of the information for the five indexes. At last，the composite index rank of the four systems was got by the integrated equation. The mathematical model can be used for comprehensively evaluating the index of light and small sprinkler irrigation system and provide proofs for optimal design of the sprinkler irrigation system.