The invention discloses a piston type electric submersible pump high-temperature protector. The piston type electric submersible pump high-temperature protector comprises a shaft. The upper end of the shaft is connected with an upper connector, and the middle portion of the shaft is connected with a middle connector. A piston cavity is formed between the upper connector and the middle connector. A piston device is movably arranged in the piston cavity and divides the piston cavity into a piston upper cavity and a piston lower cavity. The shaft is sleeved with a shaft protection pipe. A shaft protection pipe gap is formed between the shaft protection pipe and the shaft. One end of the shaft protection pipe gap communicates with an upper connector gap, and the other end of the shaft protection pipe gap communicates with a middle connector gap. The lower end of the shaft protection pipe is connected with the middle connector through a shaft protection pipe connector. The shaft protection pipe connector is provided with a second communication hole, and the piston lower cavity communicates with the middle connector gap through the second communication hole. By means of the piston type electric submersible pump high-temperature protector, the piston device moves along with different motor oil pressures, the pressure difference of motor oil and well liquid is balanced by adjusting the volume of the piston upper cavity and the piston lower cavity, and the heat expansion breathing function of the motor oil is achieved.