The development characteristics of natural fractures are restricting the efficient development of low permeability reservoirs, but the existing methods not only cannot achieve a quantitative characterization of natural fractures, also cannot achieve quantitative analysis of their effect on permeability. Therefore, based on fractal theory, SEM technology, image processing and permeability measurement were used to solve this problem in continental shale reservoir. Results show that fractal dimension of natural fractures in parallel bedding direction is much larger, natural fractures are more developed and have better fractal characteristics compared with vertical bedding direction. However, the permeability of cores with parallel bedding is much smaller, which is 1/7 of that of cores with vertical bedding. Meanwhile, the permeability of cores with vertical bedding increases with the fractal dimension of natural fractures increasing, while the permeability of cores with parallel bedding decreases with the fractal dimension of natural fractures increasing. The results are of great significance for guiding the efficient development of oil and gas in continental shale reservoir.