In order to improve the problems of low drying efficiency and uneven drying in hot air drying technology, an infrared-hot air combined dryer was designed. The influence law of air distribution chamber on flow field distribution as the core component of dryer was analyzed. Based on the airflow control equation and the standard k-ε turbulence model, the CFD software was used to conduct numerical simulation analysis on the air distribution chamber. The flow characteristics of the airflow in the airflow distribution chamber were obtained, and the cavity thickness H of the original physical model were optimized and tested. The calculation results showed that the speed deviation ratio (E) and the non-uniformity coefficient (M) can be significantly improved by the addition of the uniformly distributed air plate. The optimized model of airflow distribution chamber with the cavity thickness H=100mm can solve the phenomenon well that the airflow distribution was non-uniformity. The E and M values of the air outlet were decreased from 44.9% and 30.2% to 7.2% and 7.0%, respectively. The results showed that the average speed error was 4.21%, and the relative error of M and E values was 1.4% and 1.48%, respectively. This showed the design was reasonable and the effect of uniform airflow was obvious. The performance of the device was tested with noodles. The results showed that the drying time of infrared-hot air combined dryer was 50min, which was 16.7% shorter than that of hot air drying alone.