The invention discloses a method for separating antimony from a hydrochloric acid-chloride salt solution. The method comprises the steps of adding an oxidizing agent into the hydrochloric acid-chloride salt solution, controlling reaction conditions, oxidizing trivalent antimony in the solution into pentavalent antimony, and precipitating the pentavalent antimony to separate out pentavalent antimony oxide to obtain pentavalent antimony oxide precipitation slurry; and aging the pentavalent antimony oxide precipitation slurry, crystallizing and growing the pentavalent antimony oxide in the pentavalent antimony oxide precipitation slurry, and then carrying out solid-liquid separation to obtain a pentavalent antimony oxide solid and an antimony-removed solution, thereby achieving separation ofthe antimony. According to the method, the antimony can be efficiently and selectively separated out, the recovery rate of the antimony is high, the process flow is simple, and the operation is easy.