Abstract: Direct uniaxial tensile testing of coal is technically challenging, while indirect tensile tests often yield varying degrees of error. This study therefore established nanoscale molecular structure models of long-flame coal, coking coal, and anthracite. We employed a Perl-based uniaxial tension algorithm and molecular dynamics simulations to investigate the tensile behavior of these coal molecular models at the nanoscale. Results show that the simulated stress-strain curves exhibited satisfactory loading characteristics, with an explicit linear relationship in the pre-peak region and a strain corresponding to peak strength at approximately 0.3. Beyond the peak, the curves displayed pronounced strain-softening behavior. As the model density increased from 1.15 g/cm³ to 1.40 g/cm³, the uniaxial tensile strength rose steadily from 0.51 GPa to 1.41 GPa, while the degree of strain softening in the post-peak region declined with increasing density of the molecular model. At a constant density, anthracite demonstrated superior tensile strength due to its higher content of structurally stable aromatic hydrocarbons associated with higher metamorphism. Moreover, as the water content increased from 0.5 wt % to 3.0 wt %, the tensile strength declined from 0.47 GPa to 0.40 GPa. These simulations further reveal that uniaxial tensile failure in coal is primarily governed by the progressive development of pore damage within the molecular structure. Water molecules within the pores induce a "stress corrosion" effect, exacerbating the evolution of macropores in the coal matrix.