The invention relates to a pressure self-adaptive water turbine paddle for hydraulic electrogenerating, which comprises a positioning shaft, a positioning sleeve, a hydraulic cylinder, a driving mechanism, a driving shaft and a paddle, wherein the positioning shaft is of a hollow structure; the front end of the positioning shaft is connected with a generator; the tail end of the positioning shaft is connected with the positioning sleeve; the paddle is located on the exterior of the positioning sleeve; the tail end of the paddle is connected with the positioning sleeve through a rotating shaft; the hydraulic cylinder is located in the positioning shaft; the driving mechanism is located in the positioning sleeve; the hydraulic cylinder and the driving mechanism are respectively in sliding connection with the positioning shaft and the inner wall of the positioning sleeve through a positioning device; the driving shaft is located in the positioning sleeve; one end of the driving shaft is connected with the driving mechanism while the other end is connected with the tail end of the paddle; the hydraulic cylinder is connected with the driving mechanism. The pressure self-adaptive water turbine paddle for hydraulic electrogenerating is simple in structure, stable and reliable in running and low in use and maintenance cost; water flow pressure suffered by the water turbine paddle for hydraulic electrogenerating can be accurately detected; an included angle between the paddle and water flow can be flexibly adjusted, so that stable power input is supplied to the generator and the effective use scope of the hydroelectric generator is further widened.