Abstract: It lacks of the semantic expression of the mutual effects and interactions between operational entities and geographical entities and geographical phenomena in the existing simulation model of battlefield environment, and consequently, it is hard to reflect the dynamic change rules of the geographic environmental entities under the conditions of time and space. A spatio-temporal process model of battlefield geography environment based on simulation events is proposed to realize the integrated description and structured storage in spatio-temporal process semantics, so as to express the mutual effects and interactions between spatio-temporal objects from semantic perspective. In this model, the ontology method is used to comprehensively describe the spatio-temporal semantics and attribute semantics of simulation events, environmental entities and their behavioral process. Firstly, the spatio-temporal process semantic concepts are abstractly described based on object-oriented method, and the structural conceptual model is established by integrating the semantic relations and semantic operation rules. Secondly, according to the "individual-part-whole" cognitive principle of geospatial, the semantic and logical relationship of spatio-temporal process with hierarchical structure is constructed by top-down method, and semantic constraints are established based on event triggering to standardize semantic operation. Thirdly, the organization and storage structure of spatio-temporal process data is established according to the semantic features of data model, and the dynamic change process of spatio-temporal data driven by simulation event is realized through semantic mapping mechanism. Through the simulation events defined by the simulation system, and the spatiotemporal database and the geographical environment ontology database called by the model association relationship, the semantic attribute record of spatiotemporal process is realized from the data layer, which providing services for spatiotemporal data reasoning and backtracking. The specific performance is as follows: (1) the semantic description of the simulation events is the cause of the change of the environmental entity object; (2) the spatial semantics of the environmental entity objects describe the change information of the spatial location, geometric type and topological relationship of the object; (3) the temporal semantics of the environmental entity objects describe the temporal information of the object during the simulation process; (4) the attribute semantics of the environmental entity objects describe the change information of the object type, structure and function; (5) the process of entity behavior is represented by a series of operations of the attri-bute semantics of entity objects according to time series. The semantic model of spatio-temporal process is established by ontology as the core, integrating spatio-temporal object semantic information as the core to establish the overall framework of the model, describing and expressing the spatio-temporal semantics simultaneously, to form an object-oriented structure system that conforms to the cognitive law. Compared with the traditional simulation model structure, the dynamic changes of the battlefield geographical environment and the interaction and influence with the simulation events are reflected from the semantic point of view, making the change of spatio-temporal data conform to the development law of battlefield simulation, so the semantic correlation between spatio-temporal data and event information is strengthened by the function, improving the theory and method of dynamic modeling of battlefield environment. In the further work, the dynamic evolution mechanism of spatio-temporal data under the condition of continuous events, the extensibility and reusability of data semantic model, and the application and implementation of the model in complex systems will be further studied and explored to meet the needs of future systems.