The present disclosure provides a sensor pixel, an ultrasonic sensor, an OLED display panel and an OLED display device, in which the sensor pixel includes a base substrate, a piezoelectric transducer and a sensor pixel circuit arranged on the base substrate; the energy sensor is connected to a first signal input terminal and the first node; the sensor pixel circuit includes a signal node control subcircuit for controlling the first node according to a signal of the reset signal terminal and a signal of the second signal input terminal, a drive subcircuit for providing a detection signal to the second node under the control of a signal of the first node, and a read subcircuit for providing a signal of the second node to the signal read line under the control of the read signal terminal.