Disclosed is an impeller mechanical blade top clearance leakage compound passive control method. Blade tip grooves and tip blade spontaneous jet flows of two passive blade top clearance leakage restraining methods are reasonably combined to form the compound passive control method, on the basis of the physical nature of the compound passive blade top clearance leakage control method, the blocking effect caused by spontaneous jet flow reverse leakage jetting and the groove throttling expansion effect are overlaid to strengthen the blade tip leakage control, according to the compound passive blade top clearance leakage control method, three combination schemes shown in the figure 2 are derived, spontaneous jet flow inlets are formed in the pressure faces of the blades and close to the blade tips, and according to the difference, spontaneous jet flow outlets are different from opposite positions of the grooves. The blade tip leakage restraining is reinforced, and the aim of improving the impeller efficiency is achieved. The structure is simple, the method is convenient to implement, reliability is high, and the application range is wide.