Most gelatin hydrogels are fabricated by photocrosslinking using photoinitiators that either absorb UV light, which, in cases of high-intensity light, can cause tissue damage, or functionalize gelatin. Recently, ruthenium(II) trisbipyridyl chloride (Ru(II)bpy32+) has been studied as an initiator to induce dityrosine bond formation. In addition, continuous fibrils and small particles are often used to reinforce composite materials. Therefore, this study investigated the visible light-induced photocrosslinking of native gelatin molecules via dityrosine bond and reinforced by collagen fibrils and mesoporous bioactive glass (MBG) particles. Our results showed that collagen and MBG showed a synergistic effect on maintaining gel integrity with a dental LED curing light when the irradiation time was shortened to 30 s. Without the two reinforcing components, the gel cannot form a stable gel even when the exposure time was 120 s. The shear strength increased 62% with the collagen and MBG content of 20% compared with blank group. Furthermore, collagen and MBG enhanced gel stability in an artificial saliva solution. Moreover, the gel efficiently limited cell migration and altered cell orientation compared with that of cells in non-treated cultured dishes. These results demonstrate the considerable advantages of using native tyrosine-containing biomolecules using a dental LED curing light to polymerize hydrogels in terms of suitability and feasibility for bioadhesive in limited clinical working space such as oral disease treatment and in situ-crosslinked injectable hydrogel applications.