Abstract: The multi-band radiation flux data of 4FGL-DR3 (Fermi Large Area Telescope FourthSource Catalog Data Release 3) blazar sample are collected, which cover 6 wave-bands, e.g., radio 1.4 GHz and 143 GHz, near-infrared (J, H, K), optical (u, g, r, i, z), ultraviolet (FUV, NUV), X-ray, and \gamma-ray which cover energy bands (0.1–0.3 GeV, 0.3–1 GeV, 1–3 GeV, 3–10 GeV, 10–30 GeV, 30–100 GeV) in the 0.1–100 GeV range. These data were fitted by linear regression to analyse the correlation among different high-energy \gamma-ray energy bands, and between the \gamma-ray and the multiband radiation from radio to ultraviolet, of blazars. In the results of correlation analysis: among \gamma-ray bands, the proportion of the result with correlation coefficient greater than 0.7 is 70%, and the proportion of the results with confidence level above 95% is 95%; among \gamma-ray bands and synchrotron radiation, the proportion mentioned above is 42% with correlation coefficient greater than 0.4 and 94.4% respectively; the correlation between \gamma-ray and synchrotron radiation in the unclassified blazars (Blazar of Unknown Types, BCU) is very weak, the correlation coefficients are all lower than 0.4, the slopes in fitting among \gamma-ray bands are between BL Lac object (BLL) and Flat Spectrum Radio Quasar (FSRQ) sample. The reason may be that the BCU sample is mixture of BLL and FSRQ. The results show that Synchronous Self-Compton (SSC) scattering mechanism domains high-energy \gamma-ray in BLL, and X-ray may be the mixture of synchrotron radiation and Inverse Compton (IC) radiation.