Abstract: Aiming at the potential safety hazards of hydrogen permeation by proton exchange membrane water electrolysis, nano Pt particles are doped into the membrane by ultrasonic spraying and then Pt doped composite membrane is obtained by hot pressing to alleviate the hydrogen permeation phenomenon. Under the condition of keeping the total Pt content of membrane electrode unchanged, the effects of different Pt content in membrane on the performance and hydrogen permeation of proton exchange membrane water electrolysis are studied. The results show that nano Pt particles are successfully loaded into the membrane by ultrasonic spraying and hot pressing, thus effectively alleviating hydrogen permeation. With the increase of Pt content in the membrane, the hydrogen permeation flux decreases, but the electrolytic performance also decreases because of the gradually increasing ohmic loss. Considering the hydrogen permeation and electrolysis performance, the optimal Pt content in this paper is 0.01 mg/cm²; at 0.1 A /cm² the hydrogen in oxygen content is only 0.82%. Compared with the membrane without Pt, the hydrogen permeation is reduced by 50.32%, and the electrolysis voltage is only increased by about 20 mV. During long-term operation, the electrolytic voltage and the hydrogen concentration in the oxygen are relatively stable and the hydrogen concentration in oxygen is below the lower limit of the explosion.