Abstract: It is difficult for pulsed electro-acoustic (PEA) method to detect space charge in polymer media at extreme ambient temperature due to its limitation of working temperature of contact piezoelectric materials. Therefore, it is necessary to explore new detection methods and technologies. Based on the electroacoustic conversion principle of PEA method, this paper adopts non-contact laser Doppler vibration measurement instead of contact piezoelectric detection method to conduct research on the evaluation of polymer charge accumulation based on laser vibration measurement under sinusoidal excitation. A theoretical model based on charge-acoustic-vibration signal conversion is proposed through theoretical derivation of the relationship between various physical quantities. According to the key performance parameters of laser Doppler vibrometer (LDV), a space charge experiment platform based on laser vibration measurement under sinusoidal excitation is built, and the LDV output sensitivity experiment is conducted. The velocity port is determined as the LDV measurement port. By comparing the detection of contact piezoelectric sensors and laser vibration measurement, the acoustic and vibration characteristics of the electrode surface under DC field are analyzed, and the accuracy of the proposed acoustic-vibration theoretical model is verified. Finally, the space charge and electrode surface vibration under DC field are measured with polyimide as the detection object. PEA space charge test and LDV lower electrode vibration test are both conducted for polyimide. It is found that the characteristic quantity of average bulk charge density and velocity amplitude are both appro-ximately linear with polarized electric field, and the characteristic quantity of interfacial average bulk charge density after removing interface polarized charge and velocity amplitude after removing interface polarized charge both present a three-segment distribution with the change of polarized electric field, which indicates that non-contact laser vibration measurement and traditional piezoelectric sensor detection have good consistency, and can be applied to the evaluation of polymer space charge.