Abstract: As an important method for storing strategic oil, large-scale underground water-sealed oil storage caverns have been widely used worldwide.Underground water-sealed caverns are different from other underground rock engineering, with large span, high sidewalls, super large section, and the requirements of weak vibration, small damage of surrounding rock and high stability, so these caverns are stricter with excavation blasting.Based on the special requirements of drilling and blasting of underground water-sealed oil storage cavern, the paper proposes a construction principle:large cavern is divided into small sections, and cutted into partial sections, that is we divided large section into small section and separates blasting a few times.The controlled blasting adopts duplex wedge cut, millisecond delay initiation and contour hole with smooth blasting, and selects blasting parameters comprehensively, such as diameter, depth, spacing, minimum burden, specific charge and amounts of borehole.The blasting design is given with layout of boreholes, charging and initiation sequence.Field tests show that blasting vibration, utilization rate of borehole, formation of excavation and advance per round achieve desired objectives.The blasting design of hard rock excavation with super large section gets good blasting results, and can provide reference for similar underground rock projects.