In order to investigate the sensitivity of freezing time to air temperature and velocity, and analyze the variation of the freezing conditions and freezing time of mashed potatoes in different locations, a three-dimensional unsteady numerical model was established. According to the thermo-physical properties of mashed potatoes, the process of the temperature decreasing during freezing was simulated by Fluent. The unevenness of freezing conditions and time was obtained under different air velocity-inlet and temperature-inlet. The results showed that the change in the percentage of air temperature-inlet had a greater effect on freezing time than air velocity-inlet. With the increase of the air velocity-inlet, the unevenness of the air velocity around the mashed potatoes increased, and meanwhile the unevenness of the air temperature around the mashed potatoes decreased. The variation coefficient of temperature among mashed potatoes and the unevenness of freezing time firstly increased and then decreased with the increase of air velocity-inlet, and they were minimum when the air velocity-inlet was 6 m/s. Under the same air velocity-inlet, the in-homogeneity of the temperature around the mashed potatoes is inversely proportional to the air temperature-inlet. The experimental result showed that the simulation data was in good agreement with the experimental data. The relative error of freezing time was 3.27%, and the average absolute error of temperature was 0.79 K, with the root mean square error of 2.11 K. These results reviewed some characteristics of the freezing process of mashed potatoes without packages in an air blast freezer, which could provide a reference value for the optimization of the equipment and technologies for the freezing of foodstuffs.