To eliminate the environment pollution and fire disaster caused by using oil for quenching cooling medium,cooling property of polymer cooling medium is analyzed in this article.Then quenching technology is experimented with 281A agueous solution of three different concentrations for 50CrMn steel leaf springs.Metallographic analysis and hardness testing are done for sample.After that,this is compared with the quenching deformation and medium management used for 20 # machine oil.Then,it is found out the reason that the spring over-deviation of the bending deformation of leaf spring:the cooling speed is faster than oil's when this cooling medium is below the M S point temperature of steel. At last,this paper summarizes that the problems required to be solved are decreasing the cooling speed of this medium in low temperature,adjusting concentration and decomposition when extending the use of the polymer cooling medium in the leaf spring industry.