Silk hydrogels have mechanical properties and structural features that are similar to load-bearing soft tissues, and can be implanted for tissue restoration. In the present study, we investigate silk fibroin sol-gel transition processes in detail. The effect of different surfactants and high temperature pretreatment were studied detailedly. Based on the study, a mechanism was summarized. The result showed that the surfactant accelerated sol-gel transitions while heat pretreatment decelerated sol-gel transitions. Gelation time was decreased to several hours when added surfactant with negative charge. On the contrary, gelation time was increased to dozens of days when extended the time of high-temperature processing. Upon gelation, a random coil structure of the silk fibroin was transformed into a β-sheet structure.