The invention discloses a drilling device for hydraulic engineering. The drilling device comprises a telescopic sleeve, a telescopic rotating shaft, a drill bit, a driving device and a bracket, wherein the telescopic rotating shaft is arranged in the telescopic sleeve, drives the telescopic sleeve to stretch through rotation, and meanwhile can further drive the drill bit to rotate; the driving device is used for driving the telescopic rotating shaft to rotate; the bracket is used for fixing the whole drilling device on the ground. The drilling device does not need to add drill pipes during drilling, is operated continuously, improves the working efficiency, reduces the labor intensity, and is convenient to mount and carry.