The axisymmetric and three-dimensional combustion processes of LOX/kerosene in RD-170 thrust chamber are presented in this paper. An efficient CFD solver with kerosene's finite-rate combustion kinetic model is designed. The finite volume method and LU-SGS method are adopted, while the Van-Leer scheme is used to discrete the inviscid fluxes and center scheme to the viscous fluxes. The whole calculation domain is divided into several blocks, and the 3D N-S code has been parallelized with the use of MPI to increase the calculation efficiency and reduce the calculation time. All the codes have been validated early. The parallel code solver is successfully used to calculate the combustion flow field in the liquid rocket engines and has shown that it is very efficient for the calculation. Both axisymmetric calculation results and 3-D results accord with experiment very good.