The invention relates to a charging-type portable pA micro current monitoring system. The system adopts a single lithium battery for a unit for storing and supplying electric energy, a low-power consumption and high-precision operational amplifier and a feedback circuit are adopted, with a pA-level micro current I/V conversion circuit as a core, through multiple anti-interference protection circuits, USB is selected for charging through a charging switch, system power supply is selected through a power supply selection switch, the system power supply comes from the USB in match with the lithium battery, and monitoring on the pA micro current is completed. The charging-type portable pA micro current monitoring system can be used as a portable measurement instrument and can be used indoors, outdoors and other places in need of monitoring, power supply by the lithium battery can be realized both indoors and outdoors, and power supply by the USB is also realized. The size of the monitor of the invention is only the size of a palm, the weight is light, carrying is facilitated, the monitoring precision is high, the price is low, the testing is convenient, and a corresponding conversion voltage value can be tested when to-be-monitored micro current is inserted according to requirements.