A numerical simulation for the flue gas and process sides of a coking furnace with floor gas burners was conducted. The computational fluid dynamics (CFD) approach was employed to simulate flow, combustion, and heat transfer in the furnace. The process-side conditions were calculated with a special program. The simulation provides detailed information about the flue gas velocity, temperature fields, and process conditions for this type of coking furnace. Good agreement is obtained between industrial measurement and simulated excess air coefficient, outlet temperature of flue gas, and outlet pressure on the process side. Moreover, the simulated results indicate that there are hot spots on the tubes, located at the height of 1.5−2.5 m. That is consistent with the actual phenomenon of industrial coking furnaces. To investigate the effect of furnace structure on physical field distribution and process-side conditions, a comparative simulation case with more wide spacing of burners to walls was conducted. Results indicate that the comparative case improves the uniformity of heat flux distribution, obviously, which is beneficial for the run length of coking furnaces.