The invention provides a preparation method of a low metamorphic coal depolymerizing substance-copper-based catalyst, and belongs to the technical field of catalysts. The preparation method comprisesthe following steps: performing oxidizing depolymerizing reaction in an oxygen environment after low metamorphic coal is mixed with a sodium hydroxide solution to obtain a low metamorphic coal depolymerizing substance; and performing coordinated complexing reaction after the obtained low metamorphic coal depolymerizing substance, soluble copper salt and water are mixed to obtain the low metamorphic coal depolymerizing substance-copper-based catalyst. According to the preparation method, the low metamorphic coal depolymerizing substance-copper-based catalyst is prepared by performing the coordinated complexing reaction on the depolymerizing substance which is obtained after low metamorphic coal is depolymerized and copper ions at normal temperature and normal pressure without separating andpurifying; external energy is not consumed, and an organic solvent is not used; the pollution to the environment and energy consumption are reduced; the production cost is reduced; and the obtained catalyst is high in catalytic efficiency.