Abstract: For analyzing quantitatively the electromagnetic environment influencing factors and making them in order, the GM(1, n) model of small samples was put forward to synthesize the equipment efficiency and the electromagnetic environment influencing factors. Its corresponding algorithm was introduced. Also, to improve the modeling precision, the optimized GM(1, n) model and algorithm were presented optimal weight processing of background values. The rationality and validity of the proposed method above were verified through GM(1,4) modeling and optimized GM(1,4) modeling for the reconnaissance probability of a electronic equipment and 3 interrelated electromagnetic environment influencing factors. The results show that the relation between the primary and secondary factors that influence equipment efficiency could be analyzed quantitatively.