Oil-based drilling fluid technology is widely used in the exploration and development of unconventional oil and gas resources. Well leakage is one of the most common technical problems encountered during the application of oil-based drilling fluids. To address challenges of oil-based drilling fluid such as limited options for leak-sealing materials, susceptibility to backflow, and poor stability, a isomeric interlocking leak-sealing material was developed. This material utilizes rubber, modified nano-micron materials, stearic acid, coupling agents, anti-aging agents, and accelerators as raw components. Dry mixing techniques were employed to reinforce the rubber, followed by compression molding to create an interlocking, heterogenous structure. The isomeric interlocking leak-sealing material features a triangular pyramid and three mortise-and-tenon interlocking structure. Under pressure differentiace, it deforms and compresses, enabling interlocking between particles to enhance structural strength. Particle size ranges from 1-5 mm with temperature resistance exceeding 150℃ and density of 1.45-1.5 g/cm3. It exhibits excellent lipophilicity and dispersivity in oil-based drilling fluids with expansion rate in diesel fuel below 5% and the elastic deformation coefficient of 0.3-0.4, ensures superior elasticity. It seals fractures of varying widths under pressure exceeding 4 MPa. After entering the formation under positive pressure difference, the isomeric interlocking leak-sealing material undergoes interlocking and deformation. It enhances the material's retention and structural strength within the leak-sealing layer, thereby improving pressure-bearing performance. Field testing in shale gas wells demonstrated successful leak-sealing on the first attempt, meeting the requirements for safe, rapid, and efficient drilling of horizontal wells in shale oil/gas and tight oil/gas reservoirs.