Abstract: With the application and popularization of rapid casing running in drill pipe technology, the problem of hole collapse while drilling in the layer-through borehole is still existing, the normal on-off type drill bit has the problem of short bit life and low drilling efficiency in the construction of the rock section of the layer-through borehole. For this problem this paper introduces a new type of three-winged on-off type PDC drill bit which has been used in Zhujidong Coal Mine which belongs to Huainan Mining Group, the average drilling life of the two bits is 436.4 m, the service life of the bit increased by 36.3%; the drill bit is in the rock section construction, the drilling efficiency is 16 m/h to 18 m/h, the drilling efficiency increases about 40%, the test bit solves the existing problem, the test results are good.