The invention discloses an energy-saving method and device for four-effect concentration and crystallization of itaconic acid, which can achieve the continuity of concentration and crystallization of an itaconic acid solution, that is, a stock solution enters a pre-heater continuously and is subjected to water evaporation through one-effect/two-effect/three-effect/four-effect heating evaporators and one-effect/two-effect/three-effect/four-effect separators, the secondary vapor separated from the previous-effect separator enters the pre-heater or the next-effect heating evaporator to thermally evaporate materials, and meanwhile, crystals separated from the four-effect separator are pumped out by a crystal slurry pump continuously, so that a process that feeding, concentration via evaporation and crystal discharge can be operated in different periods can be realized, which can allow the materials to form a large amount of crystals in the four-effect separator, thereby improving the productive capacity and product quality, increasing the equipment utilization rate and reducing the vapor consumption by 50%.