The invention discloses a method for separating mercury, selenium and lead from nonferrous acid mud. The method comprises the steps of separating the selenium through pressurization oxidation leaching; separating the mercury from a leachate containing the mercury and the lead; and separating the lead from a filtrate containing the lead. The method has the beneficial effects that by means of a pressurization oxidation leaching technology, the metals of the selenium, the lead and the mercury in the acid mud can be efficiently separated, the fixation rate of the selenium in the acid mud is 95% ormore, meanwhile, the valuable metals of the mercury and the lead can be efficiently recovered, and the recovery rate is 98% or more; and the process is simple, the equipment investment is less, the recovery efficiency of the valuable metals is high, and the like.