The invention provides a silicon-on-insulator (SOI) eight-transistor static random access memory (SRAM) unit and a fabrication method thereof. The unit comprises a first phase inverter, a second phase inverter and an acquisition tube, wherein the first phase inverter comprises a first P-channel metal oxide semiconductor (PMOS) transistor and a first N-channel metal oxide semiconductor (NMOS) transistor, the second phase converter comprises a second PMOS transistor and a second NMOS transistor, the acquisition tube comprises a third NMOS transistor, a fourth NMOS transistor, a fifth NMOS transistor and a sixth NMOS transistor. In the SOI eight-transistor SRAM unit, tunneling diode structures are embedded into sources of the four transistors forming the first phase inverter and the second phase inverter, power consumption leakage and threshold voltage drift of the transistors caused by a floating body effect and a parasitic triode effect in a partially-depleted (PD) SOI device can be effectively suppressed on the condition of no increase on device area, and the noise resistant capability of the unit is improved; moreover, the fabrication method also has the advantages of simple manufacturing process and the like, and can be completely compatible with an existing logic process; and a central symmetric structure and a sharing structure between units are employed in the unit, so that a storage array is convenient to form, and the design period of an SRAM chip is favorably shortened.