Method of preparing waste water-free 2-carboxyethylphenyl hypophosphite according to the present invention, with the following steps: (1) adding 1.0 mol of dichlorophenylphosphine to a reaction vessel, stirring and heating to 80°C, then adding 1 mol of acrylic acid drop by drop, followed by raising the temperature to 110°C, maintaining the reaction at this temperature for 3 hours, and then cooling down to 50°C after completion of the reaction; (2) adding to the reaction solution obtained in step (1) 2.0 mol dichloropropane (secondary use of mother liquor, material supplement), stir thoroughly; (3) slowly add 1.0 mol water dropwise to the mixture of step (2) under stirring to carry out the hydrolysis reaction of the chlorine chloride intermediate, after the dropwise addition is completed, heat to 90 ℃, maintain for 3 hours, and then cooled to 20 ℃, to generate 2-carboxyethyl phenyl phosphinic acid, and to recover hydrochloric acid as a by-product; (4) the solid-liquid mixture obtained from step (3) is subjected to the following reaction ) the solid-liquid mixture obtained in step (3) was filtered, and the solid was washed with dichloropropane, and after filtering again, the solid was placed in an oven and baked at 130°C for 2 hrs to obtain 2-carboxyethylphenyl hypophosphite, and the mother liquor was recovered in the next batch of production. 2-carboxyethylphenyl hypophosphite showed a yield of 98.0%, a melting point of 160.2°C, an acid value (mgKOH/g) of 522, and a phosphorus content of 14.35%, and the product quality was excellent.
