The invention discloses a method for non-saponification extraction and separation of light rare earth elements. After a compound extraction agent consisting of acid phosphorus type extraction agent, alkaline amine type extraction agent and solvent oil is mixed with phosphate solvent or organic alcohol solvent at 30-70 DEG C, chlorinated light rare earth liquid is extracted and separated; and the water washing and the hydrochloric acid reverse extraction are performed to finally realize the separation of La, Ce, Pr and Nd; and a mixed organic phase after the reverse extraction is returned to an extraction tank for recycling. The method pretreats the mixed organic phase consisting of the compound extraction agent and the solvent, so that such defects as high viscosity, weak mobility, easy emulsification and long phase splitting time are overcome; the method has no need to saponify the acid phosphorus type extraction agent, so that no alkali liquor consumption and no waste water emission in the extraction process are realized, but the separation capacity of a saponification extracting agent system is achieved, and the extraction grade is reduced compared with that needed by the saponification extracting agent system; and the method is a rare earth element separation process with economy and high efficiency.