Embodiments of the present invention provide an information transmission method, a user-side device, and a network-side device. The information transmission method provided in the embodiments of the present invention includes: sending, by the user-side device, a repetition factor to the network-side device; and sending, by the user-side device, a PRACH message part to the network-side device by using the repetition factor. In the embodiments of the present invention, resource waste may be reduced.