The invention discloses a low-temperature dry distillation method of coal, relates to the technical field of full and reasonable utilization of coal resources and particularly relates to a dry distillation method of coal. The method disclosed by the invention can be used for solving the technical problem that the energy consumption is high and the treatment difficulty is great as existing coal ash cannot be dry-distilled until being compressed and moulded. According to the low-temperature dry distillation method of coal, a coal preparation unit, a dry distillation unit, a dry distillation tail gas recovery unit and a dry distillation heat source generating unit are adopted. The coal gas generated by dry distillation is heated by adopting a heat storage type heating furnace as a dry distillation heat source, so that the heat value of the dry distillation coal gas is improved to the maximum extent. A dry distillation grading system is arranged, so that the amount of fine powder entering into a dry distillation furnace is reduced while improving the dry distillation efficiency, and thus the load of oil-sludge separation by a tail gas treatment system is reduced.