With the class V water standards of Surface Water Quality Standards (GB3838-2002) as a basis for evaluation, this paper monitors the water quality of Hongqi Village and Hongxing Village monitoring sections in Xiaoquan tributary of Huaxi River, and uses the single factor index method for evaluation. The monitoring results show that the water quality of the two sections falls within inferior class V, and Xiaoquan tributary can not meet the water functional requirements. The main reason for pollution lies in the pollution from the upstream sewage, and it is recommended to strengthen inter-regional water pollution control coordination mechanism and effectively address river pollution problems.