The development status of closed loop electro optic countermeasure technology was introduced. In order to obtain the forecast evaluation of photoelectric jamming effectiveness, a forecast evaluation model was built up based on BP neural network by analyzing the technical principle and influence factors of laser jamming to optical seeker, and some photoelectric jamming experiments were implemented. After the comparative analysis to forecast result and experiment result, the accuracy of the prediction model was verified. The research can provide an application foundation for feasibility analysis of this method in photoelectric countermeasure.