To improve the efficiency of geospatial data cooperation under distributed, heterogeneous and dynamic environments, the mobile agent (MA) technology was used to construct geospatial information sharing service (GISS). The characteristics of the MA technology and the advantages of its application to GISS were discussed. A four-layer service framework and a function structure based on the MA technology were designed, and a dynamic control model of MA computing was established. In addition, implementing method of MA computing was given by taking a distributed service system of the risk assessment of barrier-dam break as an application example. The research results show that the mobile agent computing can avoid the transmission of spatial data in the network, enhance data security and improve the efficiency of data cooperation.