Multiple Topological Phases with Electronic Correlation in Intrinsic Ferromagnetic Semimetal VI₃ Monolayer

2D topological materials with magnetic ordering have become hot topics due to their nontrivial band topology and quantum states. In this work, the second-order topological states and evolution of linear band crossing are successfully predicted utilizing the effective k· p and tight binding models in the intrinsic ferromagnetic VI₃ monolayer under various effective Hubble interaction U_eff. Upon inclusion of spin orbit coupling, a small bandgap (E_g-1) of 12.7 meV is opened with a Chern invariant C = -1 at U_eff = 0 eV. The E_g-1 undergoes a transition from the non-trivial state to trivial state at U_eff = 0.80 eV, accompanied by the appearance of Dirac cone. Remarkably, the increase of U_eff causes the band inversion and adjustment of crystal symmetry, resulting in two unreported coexisting topological bandgaps (E_g-2 and E_g-3). Furthermore, a gapless node-loop appears at U_eff = 1.06 eV and disappears at U_eff = 1.09 eV around Γ point. Moreover, for the first time, the existence of second-order topological states with quantized corner fractional charges (e/3) is also observed in the VI₃ monolayer at U_eff ≥0.96 eV. These results make the VI₃ monolayer a compelling candidate for exploring topological devices.