In order to study the effects of laser remelting on microstructure of composite ceramic coating prepared by plasma spraying, in view of the characteristics of laser remelting, a finite element model for analyzing the transient temperature field of three-dimensional moving laser remelting Al2O3-13%TiO2 （mass fraction）composite ceramic coating prepared by plasma spraying was established by using the employment of ANSYS parametric design language. The temperature field in the coating and substrate was analyzed. The results show that the ceramic coating cannot be total remelted due to low conductivity of ceramic when the coating is thick enough. According to the distribution of temperature field, the coating can be divided into the remelted zone, the sintered zone and the remained plasma-sprayed zone. The thickness of the remelted zone and the sintered zone is larger using a lower laser power and scanning speed under optimum parameters. The experimental results show that the composite ceramic coating forms three different zones after laser remelting, i.e. the remelted zone (fine equiaxed grains structure), the sintered zone and remained plasma-sprayed zone (lamellar-like structure). The obtained experimental results show a good agreement with the simulation results, which indicates that the established numerical model is correct and reliable.