Abstract: There are vast reserves of coalbed methane (CBM) resources in China, where the development of CBM reservoir geology theory and technology is helpful for the further breakthrough of CBM exploration and development. Based on the literature research and analysis, the research content and progress of CBM reservoir geology and characterization technology were described, and the development direction of the frontier was analyzed. The research results show that the coal reservoir geology research, whose contents include genetic types of coal reservoir, sedimentary environments, tectonism, stress feature, physical characteristics, geometrical morphology, well pattern arrangement, reservoir renovation-protection, and well pattern adjustment-optimization, is developing from macroscopic to microcosmic, qualitative to quantitative, and from single discipline to multi-discipline. CBM transport and accumulation dynamics are divided into diffusion-percolation mechanisms under the effect of gas concentration differences and hydrodynamic-buoyancy mechanisms under the effect of pressure or potential differences. Tectonic compressional stresses alter the aquifer and water barrier mainly through the deformation of the skeletal rock, which in turn affects the ability to evacuate the fluid seepage network. Sediment compaction mainly affects the pore-fracture space and throat, and too fast sediment settlement rate tends to form an anomalous high-pressure zone, which is not conducive to reservoir fluid flow. Due to the difference in temperature of fluid in three-dimensional space, the temperature difference effect often causes the fluid to be driven by Rayleigh and non-Rayleigh convection. Generally, the fluid with low temperature and high density in shallow part moves downward, while the fluid with high temperature and low density moves upward in deep part. The study of permeability has gone through four stages, including qualitative analysis based on apparent phenomena and empirical speculation, consideration of various physical and chemical effects and refinement of the influencing mechanism of various factors, quantitative characterization combined with mathematical models and numerical analysis, and fine improvement of the dynamic change of permeability for reservoir transmission medium in micro-scale. The study points out that we need careful research on the occurrence state and diffusion-migration mechanism of gas for nanoscale pore in deep structural and thermal coal reservoir, establishment and improvement in co-production technology system of unconventional coal-measure gas, confirming the changes of gas condensation and free space in the micro-and nano-pores of coal reservoirs under different temperature and pressure according to the polydispersity process of nano-pore excess adsorption.