Based on the traditional Michelson interferometer,the four-channel balancing method for micro-vibration measurement system is built. The method without using PZT to generate high frequency carrier wave realizes four orthogonal signals by using four-channel-balancing detection instead of using PGC demodulation circuit. This method overcomes the nonlinearity of PZT, simplifies the demodulation circuit,and reduces the intensity noise of laser source, simultaneously. Through the Lissajou figure which is synthesized by the four signals, the four signals are proved to be orthogonal. The experimental results show that this method can realize the measurement of micro-vibration, and the micro-vibration displacements measuring range can be up to 5～775 nm.