A simple band model using higher order non-parabolic effect was adopted for single layer molybdenum tungsten alloy disulfide (i.e., Mo1-xWxS₂). The first-principles method considering 2 × 2 supercell was used to study band structure of single layer alloy Mo1-xWxS₂ and a simple band (i.e., effective mass approximation model, EMA) model with higher order non-parabolic effect was used to fit the first-principle band structures in order to calculate corresponding the hole mobility. In addition, we investigate the alloy scattering effect on the hole mobility of Mo1-xWxS₂.