It is important to improve its electrical and optical performances of transparent conductive thin films via constructing a double-layer homogeneous heterostructure with a wide and narrow band gap. The electronic structure, optical properties, carrier mobility, charge distribution, and energy band alignment of intrinsic and doped SnO2/SnSe2 were calculated using the first-principles based on density functionalities. The results show that a potential difference existing in the intrinsic and doped SnO2/SnSe2 electronic structures causes the electrons in the system to transfer to the interface or SnSe2, and the electrons at the interface form a two-dimensional electron gas (2-DEG) in the interface gap and move at a high speed at the interface, thereby increasing the mobility of carriers, while the electrons at SnSe2 have a corresponding increase in mobility due to the absence of impurity ion scattering. The mobilities are 772.82, 5 286.04, 2 656.90 m2/(S·V) and 17 724.60 m2/(S·V), respectively, and the optical transmittance is >80%.