Heavy metal-containing initial rain sewage treatment process

The invention relates to a heavy metal-containing initial rain sewage treatment process. Relates to the technical field of sewage treatment. All to-be-treated initial rainwater enters the rainwater collecting tank and then is lifted to the primary coagulative precipitation tank through a lifting pump, chemicals are added for hexavalent chromium reduction reaction, flocculation reaction and the like, effluent after the reaction is subjected to precipitation treatment, the effluent after precipitation automatically flows into the cyanide breaking reaction tank, cyanide breaking treatment is performed by adding cyanide breaking chemicals, and the effluent after the precipitation treatment flows into the primary coagulative precipitation tank. And the effluent after cyanogen breaking automatically flows into a second-stage coagulation reaction tank. In the second-stage coagulation reaction tank, the coagulation reaction is continued by adding an agent, effluent enters the PH regulating tank, the effluent enters t