Abstract: Polymer insulating materials are widely used in the field of electrical engineering, and their polarization and carrier transport behavior in the electric field are important factors affecting the insulating properties. Measuring the polarization behavior and carrier trap parameters of polymer materials is of great significance to studying the electrical properties of insulating materials. In this paper, we designed a test system to measure the polymer piezostimulated current (PSC) spectrum under high-pressure conditions with pressure as a variable, conducted the PSC test with polymethyl methacrylate (PMMA) material as a test object, and obtained results with good reproducibility. Under the constructed physical model, combined with the parameter fitting method, the molecular activation volume of PMMA during polarization at high pressure was calculated to be 0.89×10⁻²⁸ ~1.36×10⁻²⁸ m³, and the molecular activation energy was about 0.17 eV, which verified the validity of the piezo-excited current test method.