可达2.387mg/g。The influence of drying parameters of freeze-drying on quality of pteridium aquilinum drying was investigated, and the impact of drying board temperature, drying chamber pressure and material thickness on Vc content was studied by nonlinear regressional orthogonal design. Using single-and-double-factor analysis method, the relation between experimental criteria and drying parameters was established, and the influence order of the parameters was determined. Experimental results showed that drying chamber pressure had the greatest influence than drying board temperature and material thickness. The optimal combination of the preserved quality parameters for the freeze-drying technology of pteridium aquilinum was obtained through optimized theory in nonlinear method. They were as follows: the pressure of drying chamber was 55Pa, the temperature of the board was 42.5℃, and material thickness was 16.3mm. Vc mass ratio is 2.387mg/g.