A method and an apparatus for determining beam information, and a communications device are provided. The method for determining beam information is applied to user equipment and includes: determining, based on configuration information of a target communication resource, first information of a source reference signal in a cell and/or BWP in which the target communication resource is located, where the source reference signal is associated with the target communication resource and is located in a different cell and/or BWP from the target communication resource; and determining beam information of the target communication resource based on the first information.