The die for die casting with many side holes is alwasys very complex because it has many cores to be drawn out, so everything in its design must be considered very carefully to simplify the structure of the die, thus to avoid the problem in use. Considering the problems of simplifying the structure of castings, drawing-out cores by large angle in stationary mould, drawing-out cores through an inside block in moving mould, drawing-out cores with a long distance, the design in this paper makes the complex die have high reliability.