Taking bluefin tuna as the research object， the effects of different concentrations of chlorogenic acid (200 mg/kg sample， 400 mg/kg sample) on tuna meat color， protein and fat oxidation， freshness， water distribution， muscle microstructure and other quality characteristics during low-temperature storage were investigated. Based on this， the effects of chlorogenic acid on myoglobin structure and microenvironment were further explored through Raman spectroscopy and fluorescence spectroscopy. The results showed that adding chlorogenic acid effectively delayed the browning of bluefin tuna meat， inhibit protein oxidation and fat oxidation， and maintain the freshness of the sample. Compared with the treatment group， the muscle fiber bundles of the control group samples contracted and the gaps became larger， resulting in varying degrees of breakage. Overall， the effect of low concentration of chlorogenic acid is better than that of high concentration treatment group. The multispectral results showed that chlorogenic acid had a fluorescence quenching effect on myoglobin； and the decrease of α-helix ratio was 39.2% and 28.0% in the control and CA treated groups， respectively， indicating that chlorogenic acid can effectively stabilize the secondary structure of myoglobin.