The invention discloses a technique for recovering zinc chloride from waste water in reduction process of isooctyl thioglycolate, which is suitable for waste water treatment for the reduction process of the isooctyl thioglycolate. The technique comprises the following steps: firstly, the waste water is pumped into a storage tank by a vacuum pump and stands at normal temperature for precipitation and impurity removal; then the deslagging is carried out on the rest solution through a pumping filtration tank, the precipitation tank stands at the normal temperature for precipitation, and the BaCl2 is added and stirred at the normal temperature; the rest solution is pumped into a concentration kettle by using a corrosion-resistant centrifugal pump, and after temperature rising at low speed and vacuum treatment, and the KMnO4 and the NaOH tablet are added in, stirred and precipitate. The hydrogen chloride gas in the concentration kettle becomes muriate acid through a condenser, is put into a hydrochloric acid finished product storage tank, and the concentrated ZnCl2 solution in the concentration kettle is pumped to a zinc chloride finished product storage tank by using the vacuum pump after temperature reduction. By adopting the technique, not only all the zinc chloride and all the hydrogen chloride in the waste water are recovered, the pollution of the waste water in the original technique is eliminated, but also the wastes are reduced, the economic income is added, and the economic benefit is remarkable; and the technique is simple, easy to be operated and is feasible for popularization.