Data updating method and assistance system

A data updating method implemented by an assistance system. The assistance system includes a main electronic device and a plural of slave electronic devices. Each one of slave electronic devices belongs to one of a first device group and a second device group. The data updating method includes: the main electronic device transmits target data to at least one slave electronic device of the first device group, so that each one of slave electronic devices of the first device group obtains the target data and executes an update processing procedure; one of slave electronic devices of the first device group transmits the target data to at least one slave electronic device of the second device group, so that each one of slave electronic devices of the second device group obtains the target data and executes the update processing procedure.