The present invention belongs to the technical field of material drying, and discloses a microwave and low-pressure superheated steam combined drying test apparatus and a drying method. The combined drying test apparatus is composed of a steam generator, steam opening valves, a heater, an inlet fan, an air velocity transducer, a temperature sensor, a microwave generator, a vacuum pump, an outlet fan, a net-shaped material tray, a weighing sensor, a running water valve and a drying box. The drying method comprises that low-pressure superheated steam is used as a drying medium of a closed drying system, and materials are dried by the superheated steam and microwave together. The interiors of agricultural products are heated, inside moisture transfer speed of the agricultural products is raised, drying of the agricultural products is accelerated, temperature difference between the inside and the surface is reduced, generation of thermal stress cracks is reduced, and the drying quality and the drying uniformity of the agricultural products are ensured. No dust or volatile substances are discharged into the air in the drying process, the exhaust gas is saturated steam and can be recycled, the heat utilization rate is raised and total energy consumption of drying is lowered.