The invention discloses a plasma sterilizing and disinfecting device. The plasma sterilizing and disinfecting device comprises an ionization assembly, wherein the ionization assembly is connected witha power supply and comprises a nanometer electric conduction wire which is in crisscross arrangement, and nanometer electric conduction grids are formed in the ionization assembly; and electric current generated by the power supply flows through the nanometer electric conduction grids, so that the ionization assembly generates ionization and a plasma is generated. According to the plasma sterilizing and disinfecting device and an air purifier, the high-concentration plasma can be used for sterilizing and disinfecting air, so that the problems that a conventional filter air purifier can causebacteria breeding and secondary pollution are solved, and the purifier is small in size, and convenient to use in a small space. The plasma is low in discharge voltage and discharge power, broad in application scope, and convenient to carry. The high-concentration plasma can be generated in extra-thin space, and the sterilizing and disinfecting efficacy is high. The ionization assembly is high inintensity, not liable to crack, and long in service life.