The dislocation movement model of HgCdTe/Si which is based on Masafumi's theory of GaAs/Si was modified and improved. Rapid thermal annealing is performed on HgCdTe/Si. The results of the experiments and the theoretical calculation agree closely. We have shown a reduction as much as one order of magnitude in the number of dislocations of CdTe/Si epilayers. The lowest etched pit density (EPD) values is 2.5×105cm-2 after 500 ℃ rapid thermal annealing for 1 min.