The newly developed Co-based alloy powders is taken to prepare a ceramic particles, with reinforcing Co-based alloy gradient coating on surface of Cu-Cr alloy for crystallizer through pulse laser induced reaction in-situ. The microstructure and property of the gradient coating is studied experimentally by means of analysis techniques. The result shows that large-area Co-based gradient coating has synthesized with the laser processing parameters: average power of 50 W, frequency of 15 Hz, pulse width of 3 ms, scanning speed of 4.0 mm/min, and overlapping rate of 20%-25%. There are three different elements and structure layers consisting a gradient coating on the surface of Cu-Cr alloy. The main structure of the coating is α-CoCr2(Ni, O)4 alloy phase, with Fe-Ni, Cu-Ni as the solid solution phase enwrapped in it. The number and density of carbide ceramic particles synthesized in-situ increases gradually from inside layer to outside layer in the gradient coating. Hardness of the Co alloy gradient coating increases obviously, from 94 HV (substrate) to 432 HV (the out layer of coating), and the least wear lost is 0.008 g. It can prove that the wear resistant of the Co alloy gradient coating prepared by laser induced reaction in-situ is excellent.