In order to explore the effect of soybean urease-free CaCl2 curing treatment on the long-term stability of lead and zinc contaminated soil without greatly improving the strength of cultivated soil. The long-term stability of contaminated soil under complex environment such as dry-wet cycle, freeze-thaw cycle and acid rain leaching was studied by pH value, leaching rate of heavy metal ions and occurrence forms of heavy metals in soil. The results showed that the surface strength of lead and zinc contaminated soil treated with soybean urease-free CaCl2 was significantly lower than that of adding calcium source, and the permeability coefficient increased. Under the influence of long-term environmental conditions, the pH value of soil decreased slowly and was still weakly alkaline, and the leaching rate of heavy metals increased gradually. Under the action of acid rain, with the increase of pH of acid rain solution, the content of Pb2+ and Zn2+ in the leachate decreased gradually, and all met the requirements of the code for the disposal of hazardous wastes. In addition, the effects of different types of acid rain on the repaired soil are also different, and the stability of the repaired soil under the action of sulfuric acid rain is better than that of nitric acid rain.