Abstract: The mechanical center of beam position monitor (BPM) vacuum tune in particle accelerator can be drifted comparatively large away from the magnetic center of quadrupole under the environment of foundation vibration, temperature, thermal effects, etc. We tried to apply capacitor sensor to real-time drift monitoring. Firstly, we analyzed the capacitors measurement principle, and designed the scheme of synchronous measurement of beam orbit vibration. After that, we made a dedicated test capacitor sensor, and tested the sensors linearity, resolution and frequency response with data acquisition instruments in laboratory. Results show that it can monitor 2 m relative movement and up to 300 Hz vibration frequency. Capacitor sensors can be applied to the synchronous measurement of beam orbit and relative environment parameters.