Provided are information transmission methods, network devices and terminal devices, which may reduce an access delay. The method includes that: a target cell acquires configuration information of a measured signal, the configuration information of the measured signal being used for a terminal device to send the measured signal according to the configuration information of the measured signal; the target cell determines a beam corresponding to at least one uplink transmission channel of the target cell according to the measured signal sent by the terminal device; and the target cell transmits the at least one uplink transmission channel through the beam corresponding to the at least one uplink transmission channel of the target cell.