In order to explore the mechanism on nano fish bone (NFB) improving gel strength of fish protein, effects of CaCl₂, NFB, nano hydroxyapatite (HAP) and nano hydroxyapatite and collagen (HAP and CLG) on the gelation properties of silver carp actomyosin were comparatively investigated in this study. Calcium ion concentration was the same between the CaCl₂ and NFB groups. And the particle sizes of the NFB and HAP were the same. Breaking force of the NFB actomyosin gel was the same as that of the CaCl₂ group (p>0.05), and significantly higher than that of HAP and HAP and CLG groups. Hydrophobicity, total sulfydryl group sulfydry group, and microstructure were not significantly different among the five group of actomyosin gels (p>0.05). The SDS-PAGE gel results showed that gel of myosin heave chain dimer (MHC₂) was not visible and the gels of HAP and HAP and CLG groups had a higher intensity. Meanwhile, the CaCl₂ and NFB groups had the higher intensity gels. The results indicated that NFB increased the gel strength of actomyosin gel by the means of activating endogenous TGase, which catalyzed the formation of MHC₂.