The paper introduces the barrows locks hand-clasping and molding structure molding process, and to mould plastics quality. The main body of the institution, gating system, its molding part and the assembly structure design, including gating system in the main ways and gate location layout is reasonable particularly important. Through the analysis and discusses the mould structure scheme, the working process of the mould and matters needing attention, let the reader know injection molding design procedures and processes to emerge. Agency, the complexity and plastic itself is very high, in the design side core-pulling mechanism design is the key and difficult. During design side sues the most commonly used for twitch oblique guide to finish, column is characterized by simple structure, convenient installation.