Laser interferometry based on self-mixing effect is widely used to measure displacement, velocity, vibration and distance due to compactness, robustness, as well as low cost. Self-mixing interference produced by the feedback of light from a moved target into an edge emitting laser (EEL) was experimentally investigated for sensing applications. The self-mixing velocimeter with different types of surface, values of sample time and injection current, signal process system are also discussed. The results indicate that high precision requirement can be reached with different types of surface, values of sample time 0.1 s, 1 s. Experimental results of the self-mixing velocity measurement system show that selecting proper injection current (above 1.1 times of threshold current) of EEL and null control technique can enhance signal to noise ratio (SNR) of self-mixing signal. This conclusion can help to improve the mechanism of self-mixing and optimize the self-mixing vibration measurement system.