Abstract: In this paper, the new drying method of far-infrared in vacuum was put forward on the base of analyzing drying equipment and relevant technologies available now. Its dehydrating characteristic was analyzed. Some comparison drying tests of other ways(by heated air, by far-infrared at normal atmospheric pressure, in airflow) under the same condition were made. The combined drying way by far-infrared in airflow in earlier stage and in vacuum and exchanging air in later stage was advanced with analyzing and observing the properties of their dehydrating characteristic curves of lentinus edodes. It is the best drying method in these drying ways.