The material, electrical and ultraviolet optoelectronic properties of few layers bottom molybdenum disulfide (MoS 2 ) field effect transistors (FETs) device was investigated before and after 1 MeV electron irradiation. Due to the participation of SiO 2 in conduction, we discovered novel photoelectric properties and a relatively long photogenerated carrier lifetime (several tens of seconds). Electron irradiation causes lattice distortion, the decrease of carrier mobility, and the increase of interface state. It leads to the degradation of output characteristics, transfer characteristics and photocurrent of the MoS 2 FET.