The properties of multi-walled MoS2 nanotubes have been investigated by the first principles calculations and by molecular mechanics (MM) simulations using a revised three-body force field. The density functional theory (DFT) calculations have been performed on single-, double- and triple-walled MoS2 nanotubes. The new version of the force field is able to reproduce the structure integrity of the MoS2 nanotubes at temperatures up to 700 K through the molecular dynamics simulations. Comparison of the results of first principles and MM simulations of the multi-walled nanotubes demonstrates satisfactory agreement. The results of DFT and MM simulations indicate that the difference between chirality indices of adjacent shells of a multi-walled nanotube is the main factor that determines a possibility of the nanotube to be synthesized. The structure of zigzag 12-walled nanotubes with chirality indices difference 12 and 13, simulated by MM method and using the proposed force field, is the most close to the structure of experimentally detected nanotubes.