This paper expounds working principle of pneumatic control of hydraulic machine and its advantage and disadvantage, introduces application of pneumatic logic element in hydraulic power transmission. Aiming at disadvantage of pneumatic transmission, this paper puts forward solving scheme. 阐述了液压机气动控制的工作原理,介绍了气动逻辑元件在液压传动中的应用,分析了气动传动的优缺点,并针对气动传动缺点,提出了解决方案。