本发明公开一种制备低氯含量的异氰酸酯的方法。采用复配有机盐在酸性条件下与异氰酸酯粗品反应，采用简单过滤的方式除去沉淀，用惰性气体汽提的方式进一步降低酸分，并用真空蒸馏的方式脱除残留的溶剂，该方法可以将氯代衍生物杂质含量降至0.1％以下和酸分降低至10ppm以内，同时避免副反应产生，收率可达到90％以上，由于该方法处理得到的异氰酸酯由于氯含量降低，可明显改善下游产品的制备。

The invention discloses a method for preparing isocyanate with low chloride content. A reaction is performed between a compound organic salt and crude isocyanate under acidic conditions, a precipitateis removed in a simple filtration mode, the acid content is further reduced in an inert gas stripping mode, and a residual solvent is removed in a vacuum distillation mode. Through the method, the content of a chlorinated derivative impurity is reduced to 0.1% or below, the acid content is reduced to less than 10 ppm, meanwhile, side reactions are avoided, and the yield can reach 90% or above; and the chlorine content of the isocyanate obtained by using the method can be reduced, so that preparation of down-stream products is improved obviously.