Abstract: Considering the difficulties of bilinear transformation in the engineering design, the author of the paper makes it possible for the various quality index parameters of the transfer functions to automatically transform into the digital field through the known analog system, In addition, the author also establishes a one-to-one corresponding matrix relationship. It is fast, convenient, and precise. Moreover, it is easy of regulation and optimism, thus possessing a vertain value in automatic control and the processing of digital signals.