Abstract: The success experience and fail lesson of high voltage silicon stack used in high power circuit are proposed detailly in this paper, The high voltage rectifying circuit, charging circuit of modulator, inverse peak circuit, damping circuit, return circuit of high efficient de-Q device, clamping limiter circuit and the condition and working state property of high voltage silicon stack used in such circuits are given. It is shown that the vacuum electron diode can't be replaced reliably by silicon stack made in our country in some circuits at present.