Aiming at the shortage and potential of the common used process for producing potassium chloride in Chinese salt chemical industry currently,a new technology named cold-secomposition-aieving was designed to decrease investment cost and avoid chemical residue.Experiment results showed that after the raw carnallite ores with the particle diameter above 0.246 mm from Chaerhan Salt Lake and Dalangtan Salt Lake decompose at ambient temperature the mean particle diameter of potassium chloride was about 0.1 mm,the optimal result was discovered through serial experiments of screening mesh num-ber,when the mesh size of 0.246 mm was chosen,the yield of potassium chloride was 81.0%,the separation rate of sodium chloride was 88.8% and the sodium chloride dissolved in the decomposition solution was 6.6%.It was proved that the new process of cold-secomposition-aieving method is feasible in the experiment.