The invention belongs to the technical field of fine chemical industry, and particularly relates to a method for preparing calcium cyanamide by a solvent process. The method comprises the following two steps: step 1, adding an oxide of calcium into a high-boiling-point solvent, introducing ammonia gas and carbon dioxide while performing stirring, and after the reaction is completed, performing filtration to obtain filter residues; and step 2, performing calcination on the filter residues under high-temperature conditions in nitrogen atmosphere to obtain the calcium cyanamide. According to themethod provided by the invention, the reaction is performed in a solvent, the gas is introduced while stirring is performed, so that the problems that contact in a gas-solid heterogeneous reaction isinsufficient and the reaction is not uniform are effectively solved, the reaction temperature can be effectively reduced, the reaction time can be shortened, and at the same time, the calcination temperature of a precursor is correspondingly reduced; and the raw materials used in the method have a wide source and are easy to obtain, the preparation process is economical and environmentally friendly, the quality of the calcium cyanamide product is remarkably improved, so that the method is very suitable for industrialized promotion and application.