To understand the effects TGase and calcium chloride have on the quality of Flammulina velutipes nanocellulose composite gels, this study systematically evaluated the swelling capacity, water-holding capacity, textural properties (hardness, elasticity, adhesiveness, and chewiness), freeze-thaw stability, and cooking resistance of gel samples treated with TGase and calcium chloride. Microstructures of the composite gel samples were characterized using Fourier-transform infrared spectroscopy and scanning electron microscopy. Results showed that composite gels treated with TGase exhibited the highest absolute ζ-potential value (-25.7 mV). Compared to the other treatment groups, composite gels treated with both TGase and calcium chloride showed improvement in water-holding capacity (92.16%), hardness (8.63 N), elasticity (9.68 mm), adhesiveness (5.76 N), and chewiness (45.74 mJ). Meanwhile, synergistic treatment with TGase and calcium chloride also improved the freeze-thaw stability and cooking resistance of composite gels, reduced their dehydration shrinkage and porosity, thickened pore walls, and significantly enhanced network structures. This study showed that the quality of composite gels can be improved by incorporating TGase and calcium chloride. Moreover, a synergistic effect was observed between the two in which both the quality and structure of composite gels were enhanced. These findings provide a theoretical basis for the improvement of F. velutipes nanocellulose composite gels.