In order to solve the problems: when applying equal quality method to inner and outer parts of annular liner, the shape of annular jet would be twisted or deflected, one new design method was put forward, which is entertaining not only momentum equal but also both parts of the liner collapse synchronously. With the theory of shaped charge jet formation, theory analysis was carried on. The software Autodyn was used to simulate two courses of formation of annular jet with both improved and unimproved design methods. The results of numerical simulation show that compared with traditional method, the new method can not only avoid jet flying inwardly but also improve the jet formation. It is instructive and meaningful to the design of annular jet.