An improved closing structure of a banknote machine includes: a banknote machine; a banknote machine gate, and characterized in that: a lower portion of the banknote machine gate is disposed with a bottom plate, one side of the bottom plate is extended with a protruding extension part and a fastening column, the lateral plate is disposed with a fastening column, at least one tension spring connected to the fastening column of the lateral plate and the fastening column of the protruding extension part; and a front portion of the banknote machine is formed with an accommodation space, so that the banknote machine gate is prevented from folding back after being opened via a pulling force provided by the tension spring.