The high energy proton beam has a unique Prague peak, which means that the proton loses little energy on the transmission path and the energy is mainly deposited at the end. Therefore, the applications of high energy proton beam in the treatment of cancer in vivo, while killing cancer cells, can well protect the healthy cells. This treatment is called proton knife. Traditional ac-celerator proton knife tumor therapy has made pro-gress at home and abroad, and the clinical effect is good, but the cost of treatment is expensive and difficult to be popularized.