A multi-relaxation-time pseudopotential lattice Boltzmann (LB) model was developed to simulate multiphase flow with a large density ratio (1000) and wide viscosity ratio (15), which are highly close to the realistic cavitation phenomenon. The model is validated by Laplace law and is implemented to simulate the collapse process of single and multiple cavitation bubbles. The simulation results are in accordance with the experimental results. By comparing to other LB models and numerical methods, the stability and superiority of the present model are morphologically demonstrated. The collapse pressure and the impact jet velocity on the wall are investigated, and the jet velocity on the wall shows a typical bimodal distribution, while only one perk is observed on the pressure distribution for a single bubble collapse in near-wall region. Moreover, the results indicated that the wall–bubble distance has a greater influence on the wall pressure than the bubble–bubble distance for double bubble interactions. Finally, the simulation of the bubble cluster indicated that the inner bubble has stronger collapse intensity than the outer layer bubble, while the side bubble collapse intensity is stronger than the corner bubbles. The simulation of a series of cases proves that the proposed model is a reliable tool to investigate realistic cavitation bubble dynamics.