Method for testing P-V relation of brake

The invention relates to a method for testing a P-V relation of a brake, which comprises the steps of determining a brake clearance delta and a brake rigid deformation amount delta s of the brake under set brake pressure; determining an original brake required liquid amount Vy under the set pressure; determining a theoretical brake required liquid amount V1 through the original brake required liquid amount Vy; and determining a final brake required liquid amount Vz through the theoretical brake required liquid amount V1. Through the method for testing the P-V relation of the brake, an analysis method capable of effectively predicting the P-V relation of the brake without completion of material object development is effectively solved, and an original method, which must measure the P-V relation through a test after a material object of the brake is developed, is greatly relieved and improved.