The present disclosure relates to a data upgrading method, including: transmitting a data region preparation request for preparing a data region, transmitting a length of the upgraded data packet via a block control instruction frame, wherein a node adjusts the data region according to the length of the upgraded data packet, receiving the length of the data region, and transmitting the upgraded data packet according to a predetermined sending sequence. As such, the abnormal operations may be avoided and the reliability may be enhanced.