The excellent electrical transport properties of transition metal dichalcogenides (TMDs) materials have been demonstrated in recent years. To understand the relationship between structure and properties, first-principles calculations are carried out to study the electronic structure and mobility in two-dimensional PtS₂-like systems. The effects of Se substitution and double-layer stacking on the effective mass, electron-acoustic phonon coupling, and mobility are analyzed, revealing the influences on electrical transport properties. It is found that Se substitution and layer-stacking both have more influences on the valance band maximum than the conduction band minimum. Furthermore, the hole mobility in monolayer Pt(S_1-xSe_x)₂ decreases with the increase of Se concentration x. While mobility in bilayer systems such as PtS₂-PtS₂ , PtS₂-PtSe₂ are one-order larger than that in monolayer PtS₂ because of the so small electron-acoustic phonon coupling. Therefore, our work provides the theoretical guidance that the layer stacking is an effective way to optimize and improve the electrical transport in two-dimensional TMDs materials.