根据国家“十二五”氨氮总量控制和典型行业氨氮减排的技术需求，本文选择氮肥工业作为典型，研究共性的工程减排技术决策方法。针对目前国内环境技术评估以定性判断为主，缺乏可操作性强的综合评估方法的状况，提出了以费用效益分析为核心，层次分析+灰色关联度为次重因素的综合评估新方法，确定了该评估方法的数学模型和过程算法，并结合实例进行分析计算和验证。

According to the request of emission reduction of industry and total ammonia amount control in 12th five-year plan periods,this paper investigates the comprehensive evaluation methods of emission reduction technologies---a case study of nitrogen fertilizer. Aiming at the problems of domestic environmental technologies evaluation methods are mainly based on experts’qualitative estimate and lack of comprehensive evaluation methods, cost benefit analysis and analytic hierarchy process with grey comprehensive evaluation method were combined,a kind of evaluation method of best available technology for emission reduction of ammonia in nitrogen fertilizer industry was developed．The modeling process of the mathematical model of analytic and grey integrated evaluation method was provided with an application example analyzed．