A novel acceleration sensor based on laser self-mixing interference is proposed. The structure and principle of the accelerometer are introduced. The influence of different factors on its resolution and their influencing mechanism are analyzed. The pendulous reed supported by dual flexible beam is used as the first step sensing unit. When an inertial force due to acceleration is applied in the pendulous reed, a displacement proportional to the acceleration occurrs to the pendulous reed, which changes the length of external cavity. The phase of self-mixing interference signals generated by laser which is modulated by sawtooth-wave current is a function of acceleration. All-phase spectrum analysis is applied to detect the phase of self-mixing interference signals to reconstruct the displacement of the pendulous reed and the acceleration. A simulation model of the acceleration sensor is established. The simulation results show that the scheme is feasible. Its performances are measured through experiments. Experimental results show that the resolution of the acceleration sensor is 0.19 μg, which consistant with the retical analysis. The acceleration sensor based on laser self-mixing interference can achieve a high resolution.