The aim of this paper is to simulate the thermal field in laser cladding process, especially the temperature variation, the cooling rate and the ratio of temperature gradient to solidifying rate (G/R) in solid-liquid interface. In this study, a 3D thermal FEM is established using birth and death element technique, and able to achieve temperature distribution with varying combinations of process parameters. Subsequently, the instantaneous temperature distribution and temperature curves were obtained, the cooling rate of fixed nodes was calculated. Then, for investigating the complexity process of molten pool solidification, the solidifying and cooling rate of moving solid-liquid interface have been analyzed and calculated systematically. Also, the G/R of moving solid-liquid interface has been deduced. Finally, the simulated results have been validated by the experimental phenomena, and it shows the effectiveness and feasibility of the model. (C) 2015 Elsevier Ltd. All rights reserved.