A new heat treatment method that combines carburizing or siliconizing with laser hardening treatment in the salt solution was adopted. Using this method, the laser hardening treatment can be carried out, during surface carburizing and surface siliconizing. Experimental result shows that after laser carburizing and laser siliconizing, the carbon and silicon content in the low carbon steel 20 # surface increases by twice as original steel. A hardening layer consisting mainly of martensite and bainite structure can be obtained, which surface hardness is 1.5～2 times harder than that of original sample. The wear resistance of laser carburizing and laser siliconizing samples is increased 4～7.5 times as original steel. The test of static corrosion in the 10% H 2SO 4 solution for 240 hours shows that the corrosion resistance of steel 20 # after laser siliconizing is about 40% larger than original steel.