The optical phase-locked loop(OPLL) technology is an effective-method to realize the phase coherent of laser beam. In consideration of the loop filter influence on OPLL, a new method was presented to obtain the optimized parameters of a second order passive loop filter. Firstly, a formula was deduced to design the parameters according to the definition of phase angle margin and mathematical model of open-loop transfer function. Based on MATLAB software, a parameter optimization algorithm was formulated. Secondly, in order to calculate the parameters of Raman laser optical phase-locked loop precisely, a experiment of Doppler-free absorption spectrum was designed to get the accurate gain parameter from the piezoelectric ceramic to feedback the laser. The overshoot and regulation time of unit step response were about 6.53% and 0.584 ?滋s, respectively, in the systematic performance simulation of closed-loop optical phase-locked system. Finally, by using Simulink tools to establish models and simulating the optical phase-locked loop system module, the lasers′ phase was locked at a high speed with 2 ?滋s. Therefore, the method of OPLL parameters optimization has turned out reasonable. In addition, certain guidelines can be given for the circuit devise of the optical phase-locked loop in engineering applications.