Jiyang shale oil is a terrestrial self-generated and self-accumulated reservoir with deep burial，low maturity，and high pressure coefficient. Artificial reconstruction spaces with complex flow mechanisms form after large-scale volumetric fracturing，and it isn't easy to obtain accurate physical properties of the reservoir in the stimulated spaces through conventional experiments，which presents new challenges to numerical simulation methods. In view of the unclear internal flow law of shale oil，the reservoiraround the wellbore was regarded as a grey box system，and the numerical simulation model of the horizontal well of shale oil was established based on the understanding of physical property and fracturing effect of the reservoir from the previous exploration work. The production law of the horizontal well of shale oil in Jiyang Depression was studied to investigate the internal relationship between oil production and influencing factors. The reservoir around the horizontal well was divided into an artificial main fracture zone，micro-fracture reconstruction zone，and unstimulated matrix zone in the model. By considering fracturing fluid injection into the reservoir，the production dynamics of typical horizontal shale wells of shale oil were fitted，the physical properties of the reser‐voir were deduced，and the final oil production was predicted. The influence law of the working system and fractures on develop‐ment indexes were analyzed，and the method for determining the rational well spacing for well group development was further ex‐plored，which provided support for the development and design optimization of shale oil in Jiyang Depression.