A method for identifying the working period of laser guided signal code is proposed and simulated on the basis of the characteristics of the code and identification demands. The relation between the identifying probability and the number of the laser pulses is found by the analysis of identification procedure. Simulation results show that the identifying probability can exceed 0.95 when 6 laser pulses are received, the identifying probability is unconcerned with the number of registers and the availability of the method is verified.