In order to analyze the development law of ground fissures in Xinjing Mine and prevent surface flood from pouring into the underground through ground fissures, No.15025 Face of Xinjing Mine was taken as the research object, and the surface subsidence and ground fissures development law were studied in this working face. And the relevant observation stations and observation lines were established. Through the implementation of surface subsidence monitoring in No.15025 Face, it was concluded that the maximum surface subsidence was 4 255 mm, and the subsidence center was biased towards the downhill direction of the coal seam. Through the detection of the development depth of ground fissures in No.15025 Face, it was concluded that the development depth of ground fissures was approximately linear with the width, and the ratio coefficient was 13.081. The development depth of ground fissures was approximately logarithmic with the drop, and the ratio coefficient was 1.451 3. The research results provided a basis for the mine to predict the development depth of ground fissures and prevent ground floods from entering the mine through ground fissures.