Classification of electro-optic signal environment is of great significance to the winning of an informationized war. By analyzing the elements and indicator system construction principle of electro-optic signal environment, an indicator system for electro-optic signal environment classification is established systematically. The classification judgment function is constructed by an index factor and is further modified according to the detector's ability against interference. The proposed model is based on theoretical analysis. Since the electro-optic signal environment and the anti-interference measures are considered and both qualitative and quantitative analysis principles are incorporated, calculation is carried out easily. Finally, the correctness of the model is verified in several examples.