Objective:To evaluate the effect of prevention and control measures to drinking-water-borne endemic fluorosis in Qingdao, and to provide scientific basis for formulating prevention and control strategies.Methods:From 2019 to 2021, a full coverage surveillance was carried out in 1 146 villages in 7 drinking-water-borne endemic fluorosis areas in Qingdao, including the operation status of the water improvement and fluoride reduction project, the water fluoride content in the villages, and the prevalence of dental fluorosis among children aged 8-12 years.Results:From 2019 to 2021, all the 1 146 affected villages in Qingdao had improved their water supply, and the rates of water fluoride exceeding the standard were 7.16% (82/1 146), 1.40% (16/1 146) and 3.84% (44/1 146), respectively, and the differences between years were statistically significant (χ 2 = 48.36, P < 0.001). The detection rates of dental fluorosis in children aged 8-12 years were 3.11% (803/25 856), 2.68% (629/23 460) and 3.00% (655/21 846), respectively, and the differences between years were statistically significant (χ 2 = 8.26, P = 0.016). The detection rate of dental fluorosis among children in villages with qualified water fluoride (2.85%, 1 986/69 565) was lower than that in villages with excessive water fluoride (6.32%, 101/1 597), with a statistically significant difference (χ 2 = 67.74, P < 0.001). Conclusions:From 2019 to 2021, the effect of prevention and control measures to drinking-water-borne endemic fluorosis in Qingdao is significant and the detection rate of dental fluorosis in children is low, the detection rate of dental fluorosis in villages with qualified water fluoride is significantly lower than that in villages with excessive water fluoride. In the future, we should continue to strengthen water fluoride monitoring and engineering maintenance to ensure that the water fluoride content continues to be qualified and effectively reduce the harm of fluorosis.