Quantitative measurement of the complexity of electromagnetic environment of the reconnaissance pod is an important step for constructing a realistic battlefield environment.In order to solve the problem of the quantitative measurement of the complexity of electromagnetic environment in which the reconnaissance pod is located, an analysis is made to the electromagnetic environment.Starting from main factors that cause the complexity of electromagnetic environment, combining the objectivity and subjectivity of environmental complexity factors, an algorithm that solves the quantitative measurement of the complexity of electromagnetic environment is obtained based on gray Analytic Hierarchy Process (AHP) method and combination theory.Based on this algorithm, the principle of complexity equivalent replacement is proposed to further simplify algorithm calculation.Finally, the algorithm is verified through a typical radar electromagnetic environment, and the software is formed through LabWindows CVI.Experimental results show that the proposed algorithm has certain practical significance for measuring the complexity of a complex electromagnetic environment.