A paper currency receiving system is constructed to include a paper currency take-up unit adapted for taking up paper currency inserted therein, a paper currency storage cabinet mounted in the paper currency take-up unit to collect paper currency, a paper currency holding down mechanism installed in the paper currency take-up unit and controlled to hold down inserted paper currency onto a spring-supported bearing plate in the paper currency storage cabinet, the paper currency holding down mechanism including a rack set driven by a motor through a transmission gear train to move a linkage in an out of the paper currency storage cabinet for setting collected paper currency in a stack, and a transmitter receiver module, which automatically cuts off power supply when a predetermined amount of paper currency collected in the paper currency storage cabinet.