The invention provides a device and method for purifying crude selenium through oxidation-evaporation-carbothermal reduction, and belongs to the technical field of crude selenium purification. The device for purifying crude selenium through oxidation-evaporation-carbothermic reduction comprises an oxidation device and an evaporation-carbothermic reduction device, the crude selenium is oxidized byusing an oxidation device to volatilize a main element selenium in the crude selenium, thereby efficiently separating selenium from other impurity elements to obtain a selenium oxide; and the seleniumoxide is volatilized by using the evaporation-carbothermic reduction device and the reduction reaction is carried out to finally obtain refined selenium. The invention also provides a method for purifying crude selenium by using the device, the method is simple and rapid to operate, no toxic substance H2Se is generated, and the purity of the obtained refined selenium is high. Results of the embodiment show that the purity of the refined selenium obtained through the method can reach 99.94%, the recovery rate of the selenium can reach 95.45%, and the refined selenium meets the 3N selenium standard.