Based on the single phase isentropic gas flow theory, the paper puts forward a simpler design method of waste gas efflux self-sucking device, analyzes the main working parameters and characteristic index and gives their calculation. 基于单相气体等熵流动理论,提出了一种废气射流自吸装置较为简单的设计方法,对影响该型自吸装置的主要工作参数和工作性能指标参数进行了分析,并给出了计算方法。