The invention discloses an anti-segregation agent for concrete, which belongs to the technical field of concrete additives. The anti-segregation agent for the concrete is prepared from the following components: 5 to 15 parts of coal ash, 5 to 15 parts of mineral powder, 1 to 2 parts of steel fibers, 1 to 2 parts of polyethylene glycol, 20 to 30 parts of polyhydroxy acid water reducing agent, 0.8 to 1.2 parts of tackifier, 0.5 to 0.9 part of coagulation accelerator, 200 to 300 parts of deionized water, a plurality of parts of liquid caustic soda, 5 to 10 parts of organic silicon monomers, 3 to 5 parts of oxidant and 1 to 3 parts of reduction agent. By adding the coal ash, the mineral powder and the steel fibers, not only can the compression resistance of the concrete be improved, but also the working performance and layering degree of the concrete can be effectively improved, and the anti-segregation performance is improved; and the PAM is used as the tackifier, and the PAM has a lot of -NH2, so that the tackifier has good hydrophilia, the concrete has characteristics of hydrophilia, water retention, thickening, resistance reduction, tackifying and the like. The anti-segregation agent for the concrete is wide in source of raw materials, low in cost, environment-friendly and simple in operation.