Abstract: With the development of grid technology, higher requirements are imposed on the efficiency and quality of the grid system. In this paper, the existing grid-scheduling environment is analyzed and a novel grid-scheduling model is put forward based on fault tolerance of stochastic Petri net. Grid job dispatch policy, job selection policy in computational site and performance metrics in computational grid are also discussed. The performance of computational grid based on fault tolerance is analyzed by software emulation. The numerical results show the effect on different type of jobs.