Abstract: The shale oil in the E23 reservoir of Yingxi area is characterized by the oil distributed in the whole area and high oil yield in local districts. Limited by geological understanding and engineering technology, efficient development of the reservoir hasn’t been realized over 30 years of progressive exploration and evaluation due to the poor effect of vertical wells and low natural productivity. The paper aims to research volume fracturing technology in horizontal wells and its application to realize the efficient development by increasing stimulated volume and drainage area and reducing differential pressure. Based on the reservoir geological analysis, the paper performs feasibility evaluation of volume fracturing technology and simulation of crack propagation under complex geostress conditions. The study results show that microfractures are very developed in the E23 reservoir of Yingxi area, the reservoir rock is brittle, the reservoir space is complex and the fluidity ratio is low and the ground stress condition is complex. The volume fracturing technology in horizontal wells with “large displacement, large fluid volume, high slickwater content and temporary plugging in fractures” has been adopted and complex fracture systems form. The application of the process has achieved the goals of increasing single well production and improving development effect, proving that the volume fracturing technology in horizontal wells is an effective way to efficiently develop the oil shale in the E23 reservoir of Yingxi area