This article analyses the characters of piercing process inside of automobile cover parts. It introduces the designing structure, its advantages and disadvantages in piercing process inside of automobile cover parts by a traditional process and by a new process. The traditional process is using cams across a bridge, but the new process is a creative way that is using PAD built-in standard cams. By comparing two processes, the new creative process is convenient for operations and ensures the combining moulds in one time. This mould has a tight structure and the dimensions are reduced significantly, which is benefit for shortening the moulds’ manufacturing cycle. The new process has some guiding significance for the parts by similar piecing inside process. It has been spread and applied in a cooperative company.