In this work, a two-photon resonant excitation scheme composed of a 780 nm probe beam and a 776 nm coupling beam is employed to measure the fluorescence spectra generated by exciting ⁸⁷Rb atoms to the 5D_5/2 state. Using a high-resolution spectrometer, we achieve, for the first time, multi-channel fluorescence spectral resolution of the decay from the 5D state to the ground state via the 6P and 5P levels, with a spectral resolution better than 0.5 nm. The resolved spectra include the spontaneous emission lines at 420.3 nm, 776 nm, and 780 nm, as well as the fluorescence lines at 421.7 nm, 762 nm, and 795 nm that arise from collision-induced non-radiative transitions followed by spontaneous emission. The influence of the probe intensity, coupling intensity, and their polarization combinations on the fluorescence intensity of each channel during the excitation process is investigated. The results show that increasing the probe and coupling powers causes the fluorescence signals to saturate; some fluorescence components saturate more rapidly in a neon-filled vapor cell and exhibit a decrease due to collision-induced self-absorption. Compared with linear polarization, the modulation of fluorescence intensity by polarization is more pronounced under circularly polarized light. Furthermore, the effect of collision-induced non-radiative transitions on the fluorescence intensity of each channel is studied by introducing buffer gas at different pressures into the rubidium vapor cell. The results indicate that adding Ne buffer gas accelerates the saturation and self-absorption processes, while collisions between Ne and Rb atoms promote the non-radiative transition from the 5D_5/2 to the 5D_3/2 level, thereby adding decay pathways and generating new fluorescence signals. This work deepens the understanding of two-photon excitation dynamics and collision-induced energy transfer mechanisms in alkali metal atoms, provides an experimental reference for the influence of collisional effects on fluorescence thermometry, and offers spectroscopic techniques for extending related thermometry schemes to Rydberg systems.