Heat pump dehumidifying and thermal airflow drying equipment were used to carry out drying tests on Flammulina valutipes by means of quadratic cross rotary regression design. The pattern of the effect of (1)mean airflow velocity, (2)material water content at the change over point from heat pump dehumidifying to thermal airflow drying and (3) temperature of thermal airflow on dehydration rate, energy consumption and rehydration rate of dried peoduct was probed. The optimum parameters for this drying process were provided.