The application provides a method for detecting the performance of a dispersing agent. The detection method comprises the following steps of S1, adding a dispersant solution and a polymer to be polymerized into a container to obtain a mixture; S2, heating the container to heat the mixture to a preset temperature and keeping the condition for a preset time to obtain a product; and S3, measuring theparticle size of the product, and judging the performance of the dispersing agent according to the particle size. According to the detection method, the dispersing agent and the polymer to be polymerized are added into the container, and then the heated container enables the polymer to be polymerized to react, so that the real situation in a recovery tower is simulated. In the method, the directaddition of the polymer into the container in the prior art is avoided, so that the performance of the dispersing agent can be determined more accurately.