Using nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FITR), rotational rheometer (DHR) and other methods to study the effects of different phosphate additions (mass fraction was 0~0.5%) on the hydration, structure and rheological properties of beef minced meat. The results showed that with the increase of compound phosphate content, the moisture content of beef minced meat was increased gradually by 5.87 percentage points, the cooking loss was decreased by 8.58 percentage points, and the pH value was increased from 5.7 to 6.4. The compound phosphate shortened the meat emulsion system T21 and T22(p<0.05), indicating that the binding ability to water was enhanced. As the amount of complex phosphate added was increased, the protein network pores were denser and the pore size was finer. After heat treatment, the relative content of α-helix and β-sheet was increased and the relative content of β-turn was decreased compared with beef minced meat before heat treatment. After the formation of heat-induced gel, the relative content of α-helix was gradually decreased from 34.34% to 26.76%, and the relative content of β-turn was gradually increased from 17.41% to 29.41%, indicating that the complex phosphate made the beef prion protein system tend to be unstable. The addition of complex phosphate reduced the storage modulus (G′), loss modulus (G″) and loss tangent (tanδ) of beef minced meat. The tanδ value of the treatment group with 0.2% addition of phosphate was the most intense during the heating process. It can be concluded that the composite phosphate can loosen the structure of beef minced meat, strengthen the combination with the combined water and the non-flowable water, improve the water retention, and the secondary structure of the protein tended to be disordered. When the addition amount of the composite phosphate was 0.5%, the structure was the most loose;when the addition amount was 0.2%, the water retention effect was most remarkable.