The coal gasification process is used in the commercial production of syngas as a means toward the clean use of coal. In this paper, the process of syngas production via the coal-direct chemical looping gasification process (CDCLG) is modeled under thermochemical equilibrium with the Gibbs free energy approach, and the model is developed using a complete and comprehensive simulation model. Due to the kinetic limits of char gasification, the carbon conversion efficiency is not suggested to be larger than 0.9 in the fuel reactor during the CDCLG process. Besides, the simulation results suggest the residual carbon should be burnt in the air reactor. Moreover, the effects of various conditions, which include carbon conversion, temperature, pressure and the steam feed ratio, on the input and energy output parameters, including the air feed ratio, efficiency of electricity and syngas quality, are studied and revealed in this paper.