Abstract: In order to enable the big size PCB to carry out low-temperature plasma processing, the large plasma processing equipment is designed. The equipment is composed of the vacuum system with adjustable vacuum degree, the power system with the cooling electrode and the control system based on programmable logic control (PLC) and human machine interface (HMI). The composition and operation modes of the large plasma processing equipment are introduced briefly in this paper. The design of vacuum system including the selection & calculation of the vacuum pumps and the optimization of vacuum cavity structure based on finite element is described in detail. Practice shows that the equipment can produce plasma fast and control the chamber temperature effectively.