The invention discloses a concentration process for preparing fatty alcohol ether carboxylic acid from fatty alcohol ether carboxylate. The concentration process comprises the following steps: addingfatty alcohol ether carboxylate prepared by an oxidizing method and an acid into an acidifying reactor, and carrying out an acidifying reaction to generate acidic fatty alcohol ether carboxylate in order to obtain a liquid-phase product; standing the liquid-phase product obtained in the previous step in layering equipment for layering, and introducing the layered material into a next step; separating the material being layered by standing in the previous step in liquid-liquid separation equipment to obtain a lower-layer water phase and an upper-layer material, and concentrating the upper-layermaterial obtained after separation to obtain a concentrated material; performing solid-liquid separation on the concentrated material obtained in the previous step in solid-liquid separation equipment to obtain a solid-phase material for recovery to obtain a liquid-phase material primary concentrated product as a product. The concentration process has the advantages of simple process flow, low running cost, safe and reliable process, high resource utilization rate and low energy consumption, and is a clean production process which meets the requirements of green chemical industry development.