An evaluation method based on analytic hierarchy process (AHP) is proposed to evaluate the electromagnetic environment complexity of electronic equipment. The influencing factors and principles related to the complexity of the electromagnetic environment are introduced. The evaluation index system and the calculation method of each index are analyzed. Quantitative expression form of complex electromagnetic environment is provided. An evaluation model of electromagnetic environment complexity based on decision theory is proposed by AHP. An application example is used to visually display the complexity of the electromagnetic environment in a specific area. The simulation results show that the evaluation and presentation method can comprehensively and accurately describe the complexity of the electromagnetic environment.