The present disclosure provides a pixel driving circuit and a display panel. The pixel driving circuit includes a driving module and a grayscale adjustment module. The driving module is configured to generate a first driving current corresponding to a first grayscale range under the control of a potential at a gate voltage end and a first power source voltage, and transmit the first driving current to a light-emitting element. The grayscale adjustment module is configured to adjust the driving module under the control of the first power source voltage and a first data voltage, so that the driving module generates a second driving current corresponding to a second grayscale range under the control of the potential at the gate voltage end and the first power source voltage, and transmits the second driving current to the light-emitting element.