The invention provides a network voltage sudden swell and sag fault generator and system. The network voltage sudden swell and sag fault generator comprises an uncontrolled rectification unit, a direct-current voltage stabilization unit and an inversion voltage output unit. The uncontrolled rectification unit is connected with an external alternating-current electric supply, and used for rectifying the alternating-current electric supply into pulsation direct current. The direct-current voltage stabilization unit is connected with the uncontrolled rectification unit and used for maintaining the stability and smoothness of the pulsation direct current obtained through rectification. The inversion voltage output unit is connected with the direct-current voltage stabilization unit and used for inverting the pulsation direct current obtained after voltage stability into needed alternating-current voltage. According to the network voltage sudden swell and sag fault generator and system, the sudden sag fault of network voltage can be simulated, and the sudden swell fault of the network voltage can also be simulated.