Abstract: 【Objective】 To compare and analyze the characteristics and advantages of water use efficiency method, analytic hierarchy process (AHP) and optimize the AHP method in evaluating irrigation system in the hope of seeking scientific and reasonable evaluation method. 【Methods】 Under field experiment conditions, irrigation quota was used as variables (30.0, 37.5, 45.0, 52.5 and 60.0 mm) to analyze the scientific rationality of water use efficiency method and irrigation quota determined by AHP before and after optimization. 【Results】 The water use efficiency method could approximately determine the 45.0-52.5 mm irrigation quota range suitable for the growth of drip irrigation maize under mulch, but in order to pursue the optimal yield and water use efficiency, 52.5 mm irrigation quota could be determined qualitatively suitable for the growth and development of maize under mulch drip irrigation. The evaluation results of traditional AHP method could determine the best and only evaluation value. The total hierarchy permutation weight vector Z= (0.041, 0.086, 0.422, 0.250, 0.200) was obtained through pairwise comparison matrix which experts in this field evaluated many times. That 45.0 mm irrigation quota was suitable for the growth of drip irrigation maize under mulch. Optimized AHP method not only retained the advantages of traditional AHP method, but also combined water use efficiency method to make up for its shortcomings. It strengthened the relationship between factors and levels, avoided subjective judgment and qualitative analysis. The evaluation results could scientifically and reasonably determine that the 52.5 mm irrigation quota was the most suitable for the growth of drip irrigation maize under mulch. 【Conclusion】 Compared with the traditional AHP method and the water use efficiency method, the evaluation results of the optimized AHP method are more clear, objective, and scientific. It also provides a scientific theoretical basis for the objective evaluation and decision-making of various problems in the future.