This disclosure provides an information transmission method and a communications device. The method includes: when determining that higher layer signaling is not configured with a scrambling identifier, scrambling or descrambling, by a communications device, data by using a second initial scrambling value, where the scrambling identifier is used by the communications device to determine a first initial scrambling value used for data scrambling or descrambling, and the second initial scrambling value is related to at least one or two of a cell identifier, a radio network temporary identifier, and a reserved bit. Therefore, in the embodiments of this disclosure, when determining that the higher layer is not configured with the scrambling identifier, the communications device scrambles or descrambles the data by using the second initial scrambling value. This resolves a problem in the prior art that a terminal device cannot determine an initial scrambling value used for data scrambling.