The present invention relates to a web service based adapter middleware method. The method comprises the following steps: a service adapter setting module specifying a target service type to a service encapsulating module; a service access module converting a source service to an atomic service and outputting the atomic service to a service parsing module; the service parsing module performing service parsing according to matched service type, and obtaining source data and outputting the source data to the service encapsulating module; and the service encapsulating module querying a service type library according to the target service type to obtain a service model corresponding to the target service type, and performing service encapsulating to obtain a target atomic service and output the target atomic service to a service publishing module for publishing. The system comprises the service adapter setting module, the service type library, the service access module, the service parsing module, the service encapsulating module and the service publishing module. The web service based adapter middleware system provided by the present invention employs a configurable technology and has good extensibility and versatility. Under the condition of not changing an architecture of the system, free conversion of multiple types of services can be implemented.