CoCrAlYTa-Al2O3-ZrB2 composite coating is deposited on the Co base alloy surface by laser remelting. The microstructure, phase and micro-hardness are studied using scanning electron microscope (SEM) and X-ray diffractometer (XRD)．The high temperature oxidation test is conducted. It is found that the defects of as-sprayed coating like lamellar stacking microstructure and pores are eliminated by laser remelting, and the remelted coating possesses a denser microstructure. The micro-hardness of the remelted coating at the cross section is promoted from an average of 899.47 HV to 929.484 HV. The properties of oxidation resistance are significantly improved. The increased mass of the remelted coating is 1/6 of that of the clad coating, and the oxide film of the remelted coating is homogeneous.