Objective To simulate the temperature and flow field in the infant incubator, and to discuss the reasons of low temperature in one area of the incubator. Methods Firstly,3D model of incubator was created by using 3D modeling software .Then,the steady temperature and flow field under the condition of 32°C and 36°C running mode were simulated by using computational fluid dynamics (CFD) software. The temperature of the specific monitoring points obtained by the software were compared with the actual measured temperature of the same monitoring points. Results Their trend of the temperature was basically the same. Due to the specific monitoring points is the temperature performance test key points made by national standard, which verified the validity of the model. The reason of the low temperature was found by analyzing the flow field—the local flow velocity is too low, which caused by the structure of incubator. Conclusion The study can accumulate some experience in the design of the infant incubator.