The living creature evolve into various kinds of animals after a long time, there also is the law that includes evolvement, variation and complex at the formation of all machines. The machine evolution laws were analysed and concluded from the standpoint of mechanism in this text. The diagram of evolution form listed on show reflects the internal evolution law of mechanism. The multiple development of mechanical structure relys on the evolvement of and the variation of machine parts. The birth of pioneer product also relys on the evolutionary logic to expand.