Abstract: Based on the Middle Permian Lucaogou tight oil reservoir characteristics in Changji oilfield, this paper developed the simulation model of horizontal well multistage fracturing process, and by which studied the effects of nature fractures, fracture parameters and fracture shapes on the stimulated reservoir volume (SRV) and cumulative oil production. The results show that during early stage of exploitation, fracture parameters are the main factors affecting the production of oil wells; after entering into middle?late stage, SRV has more and more control effect on the production; while the secondary fractures and the number of fractures are the main factors affecting SRV and cumulative oil production. And the effects of secondary fractures, fracture permeability, and half?length of fracture on the well cumulative production are focused on the early period of development; the effects of the spacing and geometry of fractures are focused on the middle?late stage of development. The influence of the number of fractures runs through the entire development period. The SRV values corresponding to shuttle, trumpet and uniform types of fractures are approximately the same, while the SRV value for dumbbell type of fracture is smaller