Objective The effect of Woodwardia japonica leaves wrapped fermentation on the quality of Douchi was studied. Methods Soybeans were used as raw material. The fermented Douchi without Woodwardia japonica leaves wrapping was used as the control. The effect of Woodwardia japonica leaves wrapping on changes in sensory quality soluble protein crude fat flavonoids moisture amino nitrogen and NaCl contents in fermented Douchi were investigated. The volatile flavor substances in fermented Douchi were qualitatively and quantitatively detected and analyzed by GC-MS. Results Fermented Douchi wrapped with Woodwardia japonica leaves exhibited superior sensory qualities compared with the control group showing attractive color distinct granules moderate hardness noticeable filamentous structure and a rich mellow flavor. Its soluble protein crude fat flavonoid content and moisture were significantly higher than those of the control group P < 0. 05 . Compared with the control group the soluble protein content per milliliter of Douchi solution increased by approximately 2. 63% crude fat per milliliter of Douchi solution increased by 1. 56% and the relative content of flavonoids per milliliter of Douchi solution increased by 0. 35%. A total of 48 volatile compounds were detected in the fermented Douchi wrapped with Woodwardia japonica leaves predominantly phenolic and ester compounds. Compared with the control group the main difference between them was that phenolic and ester substances were added in the experimental group wrapped with the Woodwardia japonica leaves which belong to new volatile flavor substances produced by Woodwardia japonica leaves wrapped fermented Douchi. The additional volatile compounds mainly included guaiacol maltol 2-hexen-1-ol acetate and trimethylsilyl arsine. Conclusion Fermentation of Douchi assisted by ferns significantly enhances its nutritional value and flavor quality.