Silk fibroin (SF) hydrogels of the wild silkworm species Antheraea pernyi and Antheraea yamamai were obtained from aqueous SF solutions at room temperature. Both A. pernyi and A. yamamai solutions were slow to gelate. Hydrogels of the two species of wild silkworm were obtained rapidly following ultrasonicaton at 400–500 W. The secondary structure of the freeze-dried SF hydrogels was measured by X-ray diffraction and Fourier transform infrared spectroscopy. Ultrasonication did not change the main secondary structure of the hydrogels, but it accelerated the structural transformation of silk fibroin molecules from random coil or α helix to β sheet and reduced the gelation time.