The composition and working principle of the high-efficiency vacuum pumping system are introduced. On the basis of the original water jet vacuum pumping system, SXCQ-33-Y-11 high-efficiency vacuum pumping system is added, and the steam turbine vacuum pumping system of 9 MW waste heat power station is reformed. After the transformation, the power of the new system is only 11 kW, and the working fluid is changed from easily gasified water to 32/46# oil. The water and electricity consumption is greatly reduced. At the same time, the system structure is simple, and the land occupation and maintenance are small.