In order to comprehensively and objectively grasp the current water quality of the Suichuan river，this paper adopts the monitoring data of six sections of the Suichuan river from 2011 to 2018，and selects three water quality evaluation methods，namely single factor evaluation method，comprehensive water quality identification index method and water pollution index method，to analyze the current water quality of the Suichuan river and the spatial-temporal change trend of water quality.Water quality identification index method and water pollution index method have the advantages of quantitative evaluation compared with single factor evaluation method，which can more specifically reflect the overall level of water quality of the river and describe the water quality of the river comprehensively，scientifically and reasonably.The results of the three methods show that the water quality of each section of the Suichuan river has reached the corresponding water functional zone standards over the years，and the water quality is good，the water quality meets the standard，and there are no obvious pollutants．