Fracturing of horizontal well is often applied to increase oil well productivity in low permeability reservoir, and reasonable design of fracturing parameters of horizontal well can give full play to the role of increasing productivity of the artificial fracture. This paper abstracted the corresponding geological model on the basis of reservoir geological characteristics and the present state of exploitation in M fault block in Jiangsu Oilfield, established fractured model of horizontal well considering start-up pressure gradient by using threshold pressure of Eclipse application software, and contrasted with the PEBI grid and block grid model of horizontal well. The result shows that compared with the start-up pressure gradient, the fracture shape has a relatively small influence on the simulation results. The optimal fracture interval is 90 m, the optimal fracture number is 6, and the optimal fracture half-length is 130 m. This study provides a eference for optimization of the fracture parameters of horizontal wel in Jiangsu Oilfield.