The accumulation and uniformity of the distribution of the marinade throughout the meat over time is significantly influenced the quality of marinated meat. Based on the commonly used wet-immersion marinating method. Hyperspectral imaging (HSI) was used to quantitatively analyze the diffusion dynamics of NaCl in beef, which has advantages of rapid time dimension and continuous space dimension when acquiring optical signal of samples. Additionally, finite element analysis (FEA) was used to simulate the NaCl in beef diffusion within a three-dimensional geometric representation. The distribution status of NaCl in the marinated beef was not uniform, according to the visualization findings of NaCl content based on HSI. The FEA simulation findings demonstrated that muscle tissue had a substantially greater NaCl diffusion rate than other tissues. The variability in diffusion behavior of NaCl was the primary cause of its uneven distribution in beef. In addition, based on the spectral peak displacement mechanism with NaCl content as the disturbance factor, 9 sensitive characteristic variables were extracted by two-dimensional correlation spectral analysis (2D-COS). Then the optimal quantitative analysis model was established by the long short-term memory network (LSTM) using characteristic variables, and the R