In this study, Songyuan Grain Group Storages corn grain reserves from various years were used as samples, and a three-stage micro Raman spectrometer was used to gather the spectra of individual grains of corn from multiple conditions. The regularity of its internal components changes over time was investigated using the molecular spectra produced by Density Functional Theory (DFT). The DFT theory optimised the chemical structure, and the vibration frequency associated with each molecules bond was analyzed. The partial peak location was then determined by comparing the vibration frequency to the Raman spectra of corn grains as measured in practice. Strong Raman peaks were discovered in the original spectra after pretreatment at 476, 1 006, 1 156, 1 459, 1 519, 1 597, and 1 633 cm-1. It indicated the presence of lignin, lutein, and corn starch. Measurements were made of the Raman spectra of longitudinal corn sections from various years. After spectral normalisation, the relative peak intensities and areas of all peak sites were determined. In addition to the surface-based Raman peaks, fresh Raman peaks in the 850～1 450 cm-1 range had also been discovered. With more storage years, distinct changes occur in the starch contents Raman intensity, peak area, and FWHM at 475, 863, 944, 1 260, 1 338, and 1 378 cm-1. It demonstrates how its molecular structure, substance, and makeup have distinctly altered. This modification essentially fits the corn starch aging process. The Raman peaks at 1 080 and 1 130 cm-1 revealed a significant variation in the vertical section Raman spectra of maize across three years. While the Raman peak at 1 192 cm-1 only occurs in the spectrum of maize stored in 2020, the peak strength and FWHM value varies to variable degrees, the Raman peak at 1 080 cm-1 is only present in the spectrum of corn stored in 2018 and 2019. It suggests that the reciprocal conversion of specific carbohydrate compounds in starch can be utilized as a distinctive peak to distinguish between corn samples from various years. The peak strength and peak area values were assessed by linear fitting with the year after the physical properties of the peak sites associated withlutein content were compared. The coefficients were above 0.9, and the fitting degree was good, showing that the lutein concentration declined linearly as storage duration increased. The loss of lutein has varied impacts on the vibration of chemical bonds, with the stretching vibration of the CC double bond being the most affected. It is discovered by comparing and evaluating the spectrum of lutein acquired from theoretical calculation. This study investigates the changes in the Raman spectra of corn with time using density functional theory calculations and experimental comparisons. It gives a definite basis for identifying corn years using Raman spectroscopy. It increases the application of spectroscopy in agricultural product quality detection and analysis by analysing the internal composition variations of maize in different years.