The invention discloses a coagulation-promoting composite high-efficiency dispersant for refractory castables, the coagulation-promoting composite high-efficiency dispersant for the refractory castables is prepared by taking a FDN water reducing agent, sodium hexametaphosphate and sodium aluminate as main raw materials, wherein the mass ratio of the FDN water reducing agent, the sodium hexametaphosphate and the sodium aluminate is 60: 10-30: 30-10. The composite high-efficiency water reducing agent disclosed by the invention is applicable to the fields of amorphous refractory materials such asiron channel castables, high silica fume corundum self-flowing materials, high silica fume aluminum silicon system castables and the like. Compared with the traditional pure organic dispersant, the inorganic salt electrolyte raw materials of sodium hexametaphosphate and sodium aluminate are introduced, so that the water reducing efficiency of the water reducing agent is higher, and the system ismore stable; at the same time, the proportion of the sodium aluminate can be flexibly adjusted to adjust the coagulation promoting effect of the water reducing agent to achieve the composite functionsof water reducing and low-temperature coagulation promoting.