The invention discloses a recycling method of carbide slag, which comprises the following steps of: (1) reacting the carbide slag with the solution of sodium carbonate and filtering the reaction solution to obtain filtrate B and filter residue A, wherein the filtrate B is the solution of sodium hydroxide; (2) adding the filtrate A into hydrochloric acid, heating the mixture till the mixture boilsto perform a reaction, filtering the reaction solution to obtain a filter residue C and a filtrate D, wherein the filter residue C is used as clinker for cement production; and (3) adding hydrogen peroxide into the filtrate D to perform a reaction for 10 and 20 minutes, adjusting pH value of the reaction solution to 8.5 and 9.0 by using saturated lime water, filtering the reaction solution, drying the filter residue to obtain ferric hydroxide, concentrating the filtrate to precipitate a calcium chloride dehydrate solid, processing the obtained concentrated residual liquid by using the solution of sodium carbonate, filtering the mixed solution to obtain a solid mixture of magnesium carbonate and calcium carbonate, reacting the mixture react with the solution of sulphuric acid and filteringthe reaction solution to obtain calcium sulphate solids and the solution of magnesium sulfate. The resource processing method for the carbide slag has the advantages of various byproducts, high product quality, simple process flow, small equipment investment, easy operation, mild reaction conditions, low production cost, environmental friendliness and wide application prospect.