On the basis of analysis on the stadia equation of the low light level （LLL） night vision system, the possibility is demonstrated that using pulse infrared laser array can improve the stadia of the LLL night vision system. The pseudo random laser enhancement technique is put forward to handle the limitation that the laser assistant system is easy to be detected. The pseudo random coding theory is studied, the control circuits of pseudo random laser modulating and image capturing synchronously are designed. The pulse infrared laser assistant system is established, many experiments and some observation evaluation on the experiments have been carried out. Some good results are obtained.