A closed-tube mercury-rich annealing was performed on the HgCdTe material grown by the liquid phase epitaxy(LPE)method. The influence of different heat treatment time and heat treatment temperature on the electrical properties of HgCdTe material was studied. The mercury-rich heat treatment of HgCdTe material can effectively reduce the defect size, density and dislocation density in the material, and can complete the transformation of the material from p-type to n-type. In the process, the low temperature annealing has a great influence on the electrical properties of HgCdTe materials. It is found that with the continuous increase of the annealing time, the carrier concentration of HgCdTe materials will be increased significantly. When the low-temperature heat treatment temperature changes in the range of 210－250 ℃, keeping the low-temperature heat treatment time unchanged, the carrier concentration of the HgCdTe material after the heat treatment will fluctuate within a certain range without significant changes. Through the I-V curve test and the final component test of the HgCdTe device, it is found that the HgCdTe chip with carrier concentration in the range of 1×10¹³－1×10¹⁴ cm^-3 after heat treatment has good test results.