With the rapid development of service outsourcing,the theoretical research about service outsourcing has been lagged behind the practice of development.This paper attempts to break through the limitations of the study on services outsourcing in the tertiary industry(services).Along the main line of Producer Services,service outsourcing will be researched into the first and second industries.Through great efforts of developing business process and knowledge process outsourcing,industrial structure of service outsourcing will be optimized and upgraded so that the evolution of the logic on services outsourcing has been set forth and the theory framework of the evolution of service outsourcing has been put forward,and we proved this theory with the practice of services outsourcing in the second industry.