The invention discloses a freeze-drying method for cordyceps sinensis. The method comprises the following steps: (1) collecting fresh cordyceps sinensis; (2) removing mud and cleaning; (3) grading; (4) pre-freezing: reducing the room temperature to -40 DEG C in the manner of segmented cooling; (5) sublimation drying: increasing temperature for 0.5h, increasing the temperature of a shelf to -10 DEG C, then performing sublimation drying on cordyceps sinensis at different levels in the manner of increasing temperature according to different programs, and increasing temperature from -10 DEG C to -6 DEG C; (6) desorbing drying; and (7) softening. According to the disclosed provided by the invention, 10kg of cordyceps sinensis can be freeze-dried once; the effects and nutritional ingredients are kept well; the color is from golden yellow to brownish yellow; the satiation rate is excellent; the drying efficiency is high; the cordyceps sinensis is convenient to transport and carry; and the freeze-drying method can be popularized and applied in a large scale.