The disclosure discloses a production process and application of fermented tapioca starch for baking, and belongs to the fields of starch deep processing and food processing and production. The disclosure develops a production method of the fermented tapioca starch for baking. The method includes simple steps and greatly shortens a process cycle. By using tapioca starch as a main raw material and adding a specific amount of carbon source and a specific strain, under the action of fermentation and illumination in cooperation, the structure of the starch is improved. By adding the fermented tapioca starch, the effects of increasing the size of gluten-free Mochi bread, increasing pores of the bread and improving the texture and taste of the bread are realized.