Abstract: The surfaces of HgCdTe plates irradiated by one pulse of TEA-CO2 laser with 37.5 J and energy density of 937.5 J/cm2 are examined by an optical microscope. After laser irradiation, there are large numbers of cracks and much trace of melting in the surface of the plate, and the cracks extending in (111) are the densest in laser irradiation zone. With the increase of the action number of laser pulses at repetition rate of 1 Hz, the melting is more serious, and the numbers, depth and breadth of cracks are all increased. Analyses show the destruction of HgCdTe plates is related with laser energy, action number of laser pulses at repetition rate of 1 Hz, laser field intensity, thermal stress, laser supported combustion wave and evaporation wave.