The utility model relates to a well drilling technical field that cores, a hydraulic pressure locking formula device of coring, it includes the top connection, the bearing frame, the urceolus, the drill bit, an elasticity lock sleeve and a pressurization section of thick bamboo, the top connection, the bearing frame, the urceolus is in the same place according to preface fixed mounting with drill bit top -down, there is the medial surface to be provided with the fender ring of presenting the guiding conical surface of narrow taper under the width at the inboard fixed mounting of the lower extreme of drill bit, the elasticity lock sleeve has open -ended elasticity lock sleeve for the lower part along circumference interval distribution, the male cone (strobilus masculinus) that with guiding conical surface correspond is provided with in the outside of elasticity lock sleeve, the elasticity lock sleeve passes through the male cone (strobilus masculinus) suit on guiding conical surface. The utility model has the advantages of reasonable and compact structure, convenient to use, before the drilling tool of upper part of the body, rock core locking assembly can be locked the rock core, can pull out disconnected rock core through the upper part of the body drilling tool to improve the success rate of coring, avoided appearing the empty section of thick bamboo circumstances, be applicable to homogeneity stratum and heterogeneous body stratum.