The invention discloses a magnetic roller device and a rotating information calculation method thereof. The magnetic roller device comprises a multi-pole magnet, an MCU, a plurality of Hall componentsand a roller arranged on a handwriting device. The multi-pole magnet is arranged on the roller and comprises at least a pair of magnetic poles opposite in polarity, and output ends of the Hall components are all connected with an input end of the MCU. The magnetic roller device formed by the multi-pole magnets and the roller replaces a mechanical roller and a touch roller to realize data regulation of the handwriting device, and rotating information calculation and acquisition of the magnetic roller device are realized by cooperation with the Hall components and the MCU, so that the defect oflarge size of the mechanical roller is overcome while problems of proneness to interference and accidental touching of the touch roller and poor production uniformity are solved, and small size, lessproneness to interference, low accidental touching rate and high production uniformity are realized. The magnetic roller device is widely applicable to the field of handwriting devices.