Thin film transistor, method thereby for detecting pressure, and touch device

The invention discloses a thin film transistor, a method thereby for detecting pressure, and a touch device. The thin film transistor comprises an active layer, a source electrode, a drain electrode, a first insulation layer and a piezoelectric layer, wherein the source electrode and the drain electrode are mutually separated and are both connected with the active layer; the first insulation layer and the active layer are overlapped; and the piezoelectric layer, the source electrode and the drain electrode are separated, and the piezoelectric layer and the active layer are separated through the first insulation layer.