The invention relates to the technical field of integrated circuits, in particular to a reconfigurable threshold logic unit based on an SET (Single Electron Transistor) / MOS (Metal Oxide Semiconductor) composite structure and composed of nano devices. The reconfigurable threshold logic unit comprises a four-input SET / MOS composite circuit, a first phase inverter and a second phase inverter, wherein the output ends of the first phase inverter and the second phase inverter are respectively connected with an input end of the SET / MOS composite circuit; the input end is offset, but the device parameters of the circuit are not changed, thus, the logic unit can realize OR, NOR, AND and NAND logic functions. The reconfigurable threshold logic unit is simple in structure, low in power consumption, high in integration level, higher in reconfigurability and capable of effectively realizing different logic functions of the same unit. Due to the existence of the characteristics, the reconfigurable threshold logic unit can be applied to super-large-scale integrated circuits such as an FPGA (Field Programmable Gate Array), an artificial neural network and the like with low power consumption and high integration level.