As a novel semiconductor material, Molybdenum disulfide (MoS2) has great application potential in sensors, catalysts and optoelectronic devices. In this study, we aim to investigate the unique optical properties of MoS2 by theoretically exploring the impact of thin MoS2 films with varying layer numbers on the tip-enhanced fluorescence of a single molecule confined within the nanocavity formed by an Au tip over a substrate. The influence of incidence angle, layer numbers, tip radius and tip-MoS2 film distance on the excitation field, quantum yield and fluorescence enhancement are quantitatively analyzed in detail. The results show that the presence of multilayer MoS2 film can significantly improve tip-enhanced fluorescence spectroscopy. In the strong gap-mode plasmon coupling effect, the maximum fluorescence enhancement reaches approximately five orders of magnitude when it consists of six layers under excitation wavelength of 660 nm. Furthermore, the spatial resolution of Raman and fluorescence increases with decreasing tip radius and gap distance, reaching a maximum of 2.6 nm and 3.8 nm, respectively. Our results provide a theoretical guidance for further understanding and application of the two-dimensional material in optical experiments.