Preparation method of hyperbranched polycarboxylate dispersing agent

The invention discloses a preparation method of a hyperbranched polycarboxylate dispersing agent, which comprises the following steps: by taking an amino carboxylic acid compound or acrylic acid as a main raw material, carrying out Michael addition reaction on the amino carboxylic acid compound or acrylic acid, polyacrylamide and a polyamino compound to obtain hyperbranched polycarboxylic acid in one step, and regulating the pH value to obtain a target product. According to the invention, easily available compounds are used as initial raw materials, the operation is simple, separation and purification are not needed, the reaction conditions are mild, emission is avoided, precious metal participation is avoided, the cost is low, the requirement on equipment is low, and industrial production is easy; and the product structure is stable and controllable. The hyperbranched polycarboxylate prepared by the method can be used as a novel dispersing agent for color paste, the obtained color paste is low in viscosity,