Drinking water safety is the basic requirement for safeguarding human health. In view of the safety of rural drinking water in Gansu Province, we adopted the analytic hierarchy process (AHP), entropy weight, improved TOPSIS method and obstacle degree model for the analysis. In order to establish a comprehensive evaluation index system applicable to Gansu Province and provide a scientific reference for the construction of rural drinking water safety projects, we evaluated the rural drinking water safety status of Gansu Province in 2005, 2015 and 2020, and compared the differences between the evaluation results of the improved TOPSIS method and the fuzzy comprehensive evaluation model. The results indicate that in the past 15 years, the level of rural drinking water safety in Gansu Province has gradually improved. By 2020, the rural drinking water safety level of all cities has reached the level of basic safe and above. The main obstacles to the construction of rural drinking water safety in Gansu Province are the centralized water supply rate and the tap water penetration rate. Compared with the fuzzy comprehensive evaluation model, the improved TOPSIS method has stronger objectivity and small information loss in the calculation process, which can be further applied to the evaluation of rural drinking water safety. The construction of rural drinking water safety in Gansu Province has achieved great results, and it is necessary to consolidate and improve around weak links in the future.