Solar thermal technology has prospects for the broad application of drying agricultural and associated products. Solar hot air drying technology can effectively solve storage and transportation problems for agricultural and associated products. To improve comprehensive solar energy utilization efficiency, in this study a solar hot-air drying system, based on a comprehensive solar photovoltaic/thermal utilization collector, was designed and built. In this system, amorphous silicon solar cell and polysilicon solar cell modules provide thermal and electrical energy to the system during drying. The drying characteristics of turnips and the thermal and electrical characteristics of the solar photovoltaic/thermal air collector were studied. The results showed that seven direct current fans at the air entrance and 12 internal circulation fans on both sides of the drying chamber turned on the solar drying system compared with seven direct current fans at the air drying chamber entrance that turned on the system, which shortens the turnip drying time by 10 h. The average thermal efficiency, average electrical efficiency, and comprehensive utilization efficiency of the amorphous silicon photovoltaic/thermal collector are 46.8%, 5.7% and 54.4%, respectively. The average thermal efficiency, average electrical efficiency, and comprehensive utilization efficiency of the polysilicon photovoltaic/thermal collector are 40.7%, 6.8% and 55.4%, respectively.