Abstract: The present disclosure provides a preparation method of arsenic iron alloy, which includes the following steps: ball milling arsenic powder and iron powder under the protection of inert atmosphere according to a molar ratio of 0.1˜0.35:1 or 0.35˜2:1 to obtain pretreated material; vacuum hot pressed sintering the pretreated material to obtain arsenic iron alloy. The vacuum hot press sintering process includes: placing the pretreated material in a vacuum environment; and sintering the pretreated material; in the sintering process, a pressure of 30˜50 MPa is applied to the pretreated material. The sintering process includes: heating the pretreated material from room temperature to 400˜500° C., and holding for 0.5˜1 h; and heating the pretreated material from 400˜500° C. to 600˜800° C., and holding for 0.5˜1 h. The present disclosure can obtain arsenic iron alloy with high performance and low leaching toxicity.