Among the 32 crypto-explosive breccia pipes developing in and around Qiyugou Gold District,the J7 breccia pipe is the biggest mineralized breccia pipe in the district.It takes the NW trending,outcropping length is 1 347 m,maximum width is 926 m and area is 0.71 km2.Comprehensive analysis of the original compilation results from the exploration pits of 41 constructed drill holes and 5 levels finds that there is a crypto-explosive center in J7 breccia pipe which sits on the center of the swelling part in the middle of J7 breccia pipe.At this crypto-explosive center,the breccia is relatively fragmented,the grain size of the breccia is small,the fractionation of breccia size is not obvious,the rock holes develop and epidotization is intense.The orebodies often occur at the footwall of the crypto-explosive center of J7 breccia pipe.The next-step prospecting work should focus on the north and northwest of the crypto-explosive center and the discovery of cement type gold orebodies.