A tunnel field-effect transistor and a method for manufacturing a tunnel field-effect transistor is disclosed. Source regions are located on two sides of an oxide structure, an epitaxial layer is located on a surface on a side that is of the source region and that is away from the oxide structure, and a gate structure is located on a surface on a side that is of the epitaxial layer and that is away from the source region, so that a gate electric field direction of the tunnel field-effect transistor is the same as an electron tunneling direction, and carriers on a valence band of the source region tunnel to a conduction band of the epitaxial layer at relatively high tunneling efficiency, thereby generating a steep subthreshold swing and enabling a subthreshold swing value of the tunnel field-effect transistor to be lower than 60 mV/dec to consume relatively low power.