Clarifying the spatial distribution characteristics of red tourism resources and mastering their spatial accessibility are the prerequisite basis for tourism planning to formulate the red tourism routes. The red tourism resources in Inner Mongolia of China are rich and varied, having a great ethnic regional characteristics and playing an irreplaceable role in promoting ethnic identity and forging the Chinese national community. However, the limited cognition of the spatial distribution and accessibility of red tourism resources in Inner Mongolia has seriously hindered the high-quality development of red tourism. In this study, the kernel density and geographical concentration index were used to reveal the spatial distribution characteristics of red tourism resources in Inner Mongolia. The spatial accessibility measurement model of red scenic spots was constructed based on real-time road traffic conditions obtained from the path planning function of the Amap. Geographical detectors reveal the differences in accessibility for the red tourism spots. The following results were obtained: (1) The spatial distribution of red tourism spots in Inner Mongolia has obvious regional differences, with characteristics of “large dispersion and small agglomeration”. The largest kernel density values are observed in Hohhot City and Xing’an League, especially in Hohhot City. Obvious differences are found in the types of red tourism spots in each city. Hohhot City and Baotou City have relatively complete types, but the spatial distribution equilibrium is poor. (2) The cost of travel time between red tourism spots in Inner Mongolia is high, with an average travel time of 256.229 min. The accessibility of red tourism spots in Inner Mongolia is poor, and the internal difference is significant. The range of accessibility coefficient is 0.752-1.816. The spatial distribution of accessibility of red tourism spots shows the “center-periphery” circle gradually decreasing structure. The accessibility of red scenic spots in the Hulun Buir City and Alagxa League is low. (3) The spot regional location and regional spot density had the strongest explanatory power for the difference in accessibility, and the interaction of these two factors had the greatest explanatory power. The interaction of any two factors on accessibility differentiation is a two-factor enhancement or a nonlinear enhancement relationship, and no independent or weakening relationship is observed.