The thin film transistor includes a gate electrode formed on a surface of a substrate; a first amorphous silicon layer formed on an upper side of the gate electrode; a plurality of polysilicon layers separated by the first amorphous silicon layer and formed on the upper side of the gate electrode with a required spaced dimension; a second amorphous silicon layer and an n+ silicon layer which are formed on the upper side of the plurality of polysilicon layers and the first amorphous silicon layer; and a source electrode and a drain electrode formed on the n+ silicon layer.