The hot air drying characteristics of oat potato noodles were investigated, and the compound noodles were prepared by using oat potato flour. The hot air drying characteristics of compound noodles were studied at different temperatures, air velocity and noodle thickness, and the mathematical model was established. The resulted show that the drying time will be shorter with the higher the drying temperature. Moreover, it was found that the bigger the air velocity was the smaller the noodles thickness was. Comparing with the air velocity, the temperature and the noodles thickness had more effects on the drying rate of the compound noodles, and the falling-rate period was a main stage of the hot air drying process. The Midilli model could represent the drying process of the compound noodles successfully and have a perfect fitting effect (R²＞0.9), the experimental results were in good agreement with the predicted values. Based on all of the factors, the model could providea reliable analysis and prediction for the hot air drying process of the compound noodle. The effective moisture diffusion coefficient D_eff was in the order of 10^-10 m²/s, and it increased while the drying temperature and air velocity increase or the thickness of the noodles decreased. The activation energy E_a of the dried noodle was 43.15 kJ/mol.