The invention discloses an MOA resistive current and CT capacitive current joint monitoring system which comprises a system host, a pair of soft magnetic tweezers in signal connection with the system host and a current transformer in signal connection with the system host, wherein the a penetrating core of the soft magnetic tweezers is connected to the grounding end of an end screen of a CT sample, the current transformer is connected onto a connecting circuit of an MOA sample in series, and the system host comprises a signal conditioning unit for processing signals received by the soft magnetic tweezers and the current transformer, a data acquiring unit for acquiring an output signal of the signal conditioning unit and a PC processor in both-way communication with the data acquiring unit. The MOA resistive current and CT capacitive current joint monitoring system can simultaneously monitor capacitive current of the capacitive sample and resistive current of a lightning arrester, monitor a specific value of the capacitive current to total current of the lightning arrester in real time and avoid fluctuation of voltage values. The multiple-device joint monitoring can be opened up by improving the joint monitoring system and adding a current signal acquiring channel, the shortcomings existing in an existing single monitoring system are effectively overcome, and the joint monitoring system is suitable for popularization and usage in a electric power system.