Abstract: Dashui Gold Deposit lies on the east of Dashui Gold Field,which is a magmatic hydrothermal gold deposit controlled by fault structures.Through practice,this paper summarized the ore control laws of "2 phases and 3 groups of faults".The fractures including earlier fracture F4(NWW),rotational shear structure tangent to simulta-neous F4 and late radial fracture constitute the basic tectonic framework of the ore district,forming 2 groups of ore-hosting fractures(one is composed of F4 and simultaneous rotational shear structure,the other is contact fracture of vein rock intruding along radial fractures and surrounding rock).Nearly all of the ore bodies are located in the 2 groups of ore-hosting fractures.According to the structural control of ore deposition,Au20-1 ore body was found through prospecting prediction in the deep part of Dashui Gold Deposit,achieving significant prospecting breakthrough.