According to the coding technology of the laser guidance weapon, it is necessary to carry through code identifying and pulse forecast technology for effective laser jamming. The signal de-interleaving and code identifying were deeply discussed by analyses of the coding technology. Based on the PRI arithmetic of the radar signal, a new arithmetic of de-interleaving and identifying of the signal laser-guided was advanced, which included the process of de-interleaving and identifying of the signal. This arithmetic achieved the aim of code identifying, which has been validated by Matlab. A sample project of this interfere process was implemented on FPGA and the flow was mentioned in this paper.