High energy density physics driven by intense heavy ion beams will be an important new project for the high intensity heavy-ion accelerator facility and the Dongjiang Laboratory. This paper presents an experimental investigation of ion beam-induced luminescence in a strong magnetic field background at HIRFL. The experiment utilizes a 430 MeV/u 84Kr26+ ion beam with a pulse duration of 300 ns to bombard an Al2O3 (Cr3+) solid target. The results show that the characteristic emission spectrum of the Cr3+ ion's 2E→4A2 transition is observed, and spectrum parameters significantly change with the magnetic field of the background. We present the experimental data on the shifts of the peak center (Δσave) and the broadening of full width at half maximum (WG). The changes in parameters related to the intensity of the magnetic field are discussed using atomic models. This work demonstrates the potential application of diagnosing magnetic fields by measuring characteristic spectra.