The invention relates to a dechlorination process in zinc hydrometallurgy. The dechlorination process in the zinc hydrometallurgy comprises the following steps: (1) bismuth oxide is added in leaching liquid after roasting of zinc concentrates for dechlorination to obtain bismuth oxychloride precipitates and dechlorinated leaching liquid; (2) the bismuth oxychloride precipitates are added in alkali solution for alkali washing to obtain bismuth oxide and chloride solution; and (3) bismuth oxide obtained by alkali washing is added in the acid solution for acid washing to obtain bismuth ion solution; and the bismuth iron solution is returned into the leaching liquid after roasting of the zinc concentrates for dechlorination. The dechlorination process is excellent in dechlorination effect, simple in treatment method, short in circulation period and low in unit consumption of a dechlorinating agent, and can effectively control the system chlorine ion concentration.