Although there are many works trying to make it easier and quicker, the difficulty of grid-enabled application development is still one of the stumbling blocks to employ grid as infrastructure of geo-computation. In this paper, situation is introduced to describe application requirements and available resources for users first. Based on the study on definition, acquirement, processing and matching of situation, a grid application generation model based on situation processing is proposed, which can create grid applications for geo-computation more simply and quickly. Experiments on the implementation and test show that situation processing based grid application generation model can reduce the complexity of application development in spatial information grid, and make it simpler to create grid applications for geo-computation.