The invention discloses a cash-twiddling mechanism of a cash-counting machine. The cash-twiddling mechanism comprises a base; the upper end of the base is fixedly provided with a shell; a rotating roller is rotationally sleeved with the inner cavity of the shell; accommodating grooves are uniformly formed in the surface of the rotating roller; one end of the rotating roller is connected with the rotation shaft of a motor; the motor is fixed to the side surface of the shell through a bracket; the motor is electrically connected with a controller at the side surface of the base; an exit is formed at the bottom of the shell; two sides of the exit are provided with side plates; air extracting pumps are arranged in the inner cavities of the side plates; air vents are uniformly in the surfaces of the side plates; a storage drawer corresponding to the exit is arranged in the base; the bottom of the inner cavity of the storage drawer is provided with a pressure sensor; and the pressure sensor is electrically connected with the controller. According to the cash-twiddling mechanism of the cash-counting machine of the invention, the upper end of the base of the cash-counting machine is fixedly provided with the annular shell, and therefore, the problem of cash jumping in the twiddling process of cashes can be effectively solved. The cash-twiddling mechanism of the invention has the advantages of simple structure, high automation degree, and stable and reliable cash-twiddling movement.