The Al door test piece is a kind of standard sample which is used to express the shot peening effect.. Material sae1070 spring steel, the of parabolic shot, because the residual force will enable test sheet generation a certain radian, the use of arc height tester can measure the arc height conversion to throw a shot peening intensity. Almen test piece is divided into three kinds: "n" specimen: thickness = 0.031 "(0.79 mm)" a "specimen: thickness = 0.051" (1.29 mm) "C" specimen thickness = 0.094 "(2.39 mm), need according to the shot peening intensity select suitable test piece.