Abstract: Based on the basic concept of complex electromagnetic environment in sea battlefield,a method for evaluating the efficiency of complex electromagnetic environment construction is proposed by analyzing the factors that affect the construction efficiency and Markov decision process. In this paper, the perception and planning problems in large-scale uncertain environment are layered and decomposed for complex electromagnetic environment. A more comprehensive and efficient efficiency evaluation is proposed based on the cost of environment construction. Compared with the traditional evaluation method based on cost-effectiveness ratio,this method can more intuitively and objectively show the real-time benefit transfer between different environmental conctruction schemes.