Pixel driving circuit and method and display device

The invention provides a pixel driving circuit and method and a display device. The pixel driving circuit comprises a pre-charge control unit, a storage capacitor, a driving transistor and a threshold value compensation unit. The pre-charge control unit charges the storage capacitor through power voltage at the pre-charge stage. At the threshold value compensation stage, under control of a control signal, the threshold value compensation unit and the driving transistor together control the storage capacitor to discharge until the potential of the first electrode of the driving transistor is Vdata+Vth, and at the light-emitting stage, the gate source voltage Vth compensation of the driving transistor is controlled. Vdata is the voltage of a data signal on a data line, and Vth is the threshold value voltage of the driving transistor. While the threshold value voltage of the driving transistor is compensated for, the data signal is adopted for directly controlling the driving transistor, in this way, the number of transistors can be decreased, then the space for the circuit design can be reduced, and the pixel interval can be increased.