The Bombyx mori silk fibroin gel with three dimensional structures is an important form to be developed for tissue engineering materials. In this paper, silk fibroin gels were prepared with adding polyalcohol into silk fibroin solution. The gel structure was analyzed by X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy. The results demonstrated that when adding more than 100% of polyalcohol, both of glycerol and polyethylene glycol 400 (PEG400) can accelerate the gelation process markedly. With the increase of the percentage of PEG400 and glycerol, it promoted silk fibroin molecules to cluster rapidly and inhibit silk fibroin molecules transforming from the random coil or α-helix to β-sheet in a ratio of 900% especially. Silk fibroin gels containing 100% of polyalcohol had more uniform morphology and the pores distributed uniformly.