The triboelectric nanogenerator (TENG) is a promising energy harvesting technology that can convert mechanical energy into electricity and can be used as self‐powered active sensors. However, previous studies are mostly carried out at room temperature without considering the temperature effect on the electrical performance of TENGs, which is critical for the application of electronics powered by TENGs in different regions in the world. In the present work, a TENG that worked in the single‐electrode and contact‐separation mode is utilized to reveal the influence of environment temperature on the electrical performance of TENG. The electrical performance of the TENG shows a decreasing tendency, as the temperature rises from −20 to 150 °C, which is controlled by the temperature‐induced changes in the ability of storing and gaining electrons for polytetrafluoroethylene (PTFE). The storing electron ability change of PTFE is attributed to two aspects: one is the reduction of relative permittivity of PTFE sheet as the temperature increases, and the other is the variations of effective defects such as the escape of trapped charges in shallow traps and surface oxidation under the effect of temperature perturbation. This work can provide useful information for the application of TENG in both electric power generation and self‐powered sensors in the harsh environment.