Paper quantity detection method and device, paper supply control method and device and storage medium

The embodiment of the invention provides a paper quantity detection method, a paper supply control method and device and a storage medium. The paper quantity detection method comprises the following steps: acquiring current paper twisting duration; and according to the current paper twisting time length, the longest paper twisting time length and the shortest paper twisting time length, calculating the paper remaining amount in the current paper supply box. The paper supply control method comprises the following steps: calculating the initial paper twisting time of the next paper according to the paper twisting duration and the paper supply period of the previous paper; and when the initial paper rubbing time of the next paper is reached, the paper rubbing roller is controlled to start to convey the next paper. In the embodiment of the invention, for the image forming device which is not provided with a paper quantity sensor or a paper supply box lifting plate, aiming at the dynamically changing paper remaini