本文讨论了以范德瓦尔斯气体为工质，以多方过程替代绝热过程的otto循环，给出了该循环过程的输出功和效率，并分析了多方指数n和压缩比r对循环参数的影响，通过数值计算的方法，分析得出，多方指数和压缩比都对循环参数有影响，且当多方指数的数值等于绝热指数时，循环输出功和效率最大. 

This article discusses the Otto cycle using Van der Waals gas as a working medium and replacing the adiabatic process with the polytropic process. It presents the output work and efficiency of this cycle, and analyzes the effects of the polytropic exponent n and compression ratio r on the cycle parameters. Through numerical calculations, it is concluded that both the polytropic exponent and compression ratio have impacts on the cycle parameters, and when the numerical value of the polytropic exponent is equal to the adiabatic exponent, the cycle’s output work and efficiency are maximized.