A novel tribotronic transistor has been developed by vertically coupling a single-electrode mode triboelectric nanogenerator and a MoS2 field effect transistor. Once an external material contacts with or separates from the device, negative charges are induced by triboelectrification on the surface of the polymer frictional layer, which act as a gate voltage to modulate the carrier transport in the MoS2 channel instead of the conventional applied gate voltage; the drain-source current can be tuned in the range of 1.56-15.74 A, for nearly ten times. The application of this MoS2 tribotronic transistor for the active smart tactile switch is also demonstrated, in which the on/off ratio can reach as high as approximate to 16 when a finger touches the device and the increased drain-source current is sufficient to light two light-emitting diodes. This work may provide a technique route to utilize the 2D materials based tribotronic transistors in MEMS, nanorobotics, and human-machine interfacing.