Abstract: Embodiments of the present disclosure disclose a cell selection or reselection method and a device, to resolve a problem that a terminal device cannot effectively and rapidly access a cell without taking a slice of the cell into consideration when performing cell selection or reselection. The method may be performed by a terminal device, and includes: receiving a MIB message from a cell; in a case of determining, based on the MIB message, that the cell can be a candidate access cell, reading a SIB message of the cell, where the SIB message includes slice information of the cell; and selecting one slice from slices of the cell to access based on slice information supported by the terminal device and the slice information of the cell.