In order to study the energy loss of refrigerant and the flow law of refrigerant in the condenser tube under different distribution of the condenser core flat tube, the twodimensional model of the condenser core was established, and the flow of refrigerant in the condenser pipeline was simulated by using CFD software. The simulation results of the refrigerants with 17 different flow rates were analyzed under the three structures of flat tubes: 20-13-9, 21-13-8, 21-12-9. The velocity and pressure fields under different flow rates were obtained, and the energy losses of the three structures under different flow rates were calculated. The results show that under the same conditions, the energy loss of the refrigerant in the 20-13-9 structure is the least, so the flat tube of the condenser core with the 20-13-9 structure is more reasonable. The simulation results also directly show the flow of refrigerant in the condenser core pipeline. In the whole core, the vortexs with various sizes and scales are generated during the flow process, and the transition area of the flat tube can be designed into a rounded structure to reduce the energy loss.The results reveal the flow law of refrigerant in the condenser and provide some references for the optimal design of automobile air conditioning condenser.