Abstract: In order to solve the problem of stability control of large section open-off cut in thick alluvium and thin bedrock, taking the open-off cut in 16001 working face of Zhaogu No.1 Coal Mine as the engineering background, using the research methods of field investigation, numerical simulation and field industrial practice, the stability control technology of large section open-off cut in thick alluvium and thin bedrock was studied systematically. The results show that the main factors affecting the stability of 16001 working face including complex high stress field, low strength of surrounding rock and the development of bedding cracks, lack of prestress and strength of traditional support system. In this paper, the excavation scheme of subdivided into lanes to reduce the span of roadway and the combined support technology of "high prestresse anchor net cable + anchor cable beam + monomers" are proposed.The site application results are good, the maximum subsidence of the roof is 208 mm and the maximum movement of the two sides is 170 mm, which can effectively guarantee the stability of the surrounding rock of the open-off cut and meet the requirements of installing equipment rapidly of the working face.