The invention provides a junctionless lengthways tunneling field effect transistor, comprising a source region, a drain region, a channel region, a control grid and an auxiliary grid, wherein the source region, the drain region and the channel region are formed into a whole and adopt the same doped semiconducting material; the doping concentration from the source region to a channel and the drain region is the same; the control grid and the auxiliary grid are respectively located on the two sides of the channel; at least a part of the control grid and a part of the auxiliary grid are opposite to each other; the control grid is used for controlling the breakover and closing of a device; and the auxiliary grid is used for making a semiconducting region under the auxiliary grid generate transoid. The junctionless lengthways tunneling field effect transistor has only one doping type, no PN junction is needed to be made, the process difficulty is reduced, the size reduction of the device is facilitated, a short channel effect is restrained, the switching current ratio is increased, off-state current leakage is further reduced through the distance region between the control grid and the auxiliary grid, the characteristics such as a subthreshold slope can be improved, the tunneling length is effectively reduced through controlling the thickness of a semiconductor film, and the tunneling current is increased.