A Coupled Lattice Bhatnagar-Gross-Krook (CLBGK) model was proposed with a robust boundary scheme to model the Bossinesq incompressible flows. The LBGK method is a powerful approach, but is also computationally demanding. Therefore, parallel computing was implemented, and the codes were run on the parallel computer “Lenovo DeepComp 1800” with 24 nodes written in C++ using the Message Passing Interface (MPI) library. Numerical results for natural convection in a cavity with the Rayleigh number (Ra) ranging from 10~6 to 4×10~10 were presented, and found to agree well with the previous work. And with the increase of the resolution rate, the accuracy has been greatly improved. In addition, new models were set up by applying different equilibriums to the CLBGK model to simulate the same problem, which all yield sound results. A coupled Lattice Bhatnagar-Gross-Krook (CLBGK) model was proposed with a robust boundary scheme to model the Bossinesq incompressible flows. The LBGK method is a powerful approach, but is also computationally demanding. Thus, parallel computing was implemented, and the codes were run on the parallel computer “Lenovo DeepComp 1800” with 24 nodes written in C ++ using the Message Passing Interface (MPI) library. Numerical results for natural convection in a cavity with the Rayleigh number (Ra) ranging from 10 ~ 6 to 4 × And with the increase of the resolution rate, the accuracy has been greatly improved. New additions have been by applying different equilibriums to the CLBGK model to simulate the same problem, which all yield sound results.