Abstract: The poly(3,4-ethyl-enedioxythiophene): polystyrenesulfonate functionalized Te nanowires (Te@PEDOT:PSS) composite films were in situ synthesized using a one-step thermal reduction process. Then the Te@PEDOT:PSS composite films were immersed into AgNO₃ solutions with different concentration to prepare Ag₂Te@PEDOT:PSS composite films. By introducing Ag⁺ into the Te@PEDOT:PSS composite films, P type Te@PEDOT:PSS composite films was transformed to N type Ag₂Te@PEDOT:PSS composite films. FESEM, TEM, XPS, and XRD were used to analysis the reaction mechanism between AgNO₃ and Te@PEDOT:PSS composite films. Also, the thermoelectric properties of the Ag₂Te@PEDOT:PSS composite films as a function of AgNO₃ concentration were measured. The electrical conductivity of Ag₂Te@PEDOT:PSS composite films first increases as the increasing AgNO₃ concentration, and then decreases due to the formation of TeO₂. The Seebeck coefficient of the Ag₂Te@PEDOT:PSS composite films decreases significantly with the increasing concentration of AgNO₃. The phenomenon can be contributed to the N type conduction of Ag₂Te, and when the amount of electron provided by Ag₂Te is larger than the amount of hole from Te, the conduction mechanism changes from P type to N type. As the further increasing concentration of AgNO₃, the absolute value of Seebeck coefficient of the Ag₂Te@PEDOT:PSS composite films increases. And the value reaches (−55.9±3.3) μV/K when the concentration of AgNO₃ is 10 mmol. The N type Ag₂Te@PEDOT:PSS composite film shows a maximum power factor of (8.4±0.7) μW/(m·K²) with 20 mmol AgNO₃.