The method includes: obtaining, by UE, UE capability information of the UE; if the size of the UE capability information exceeds the maximum tolerance that can be processed by the PDCP layer of the UE, splitting the UE capability information into at least two pieces of part UE capability information, where each piece does not exceed the maximum tolerance that can be processed by the PDCP layer; and reporting at least one piece of part UE capability information to a network side device. According to this method, the UE capability information is split on a UE side, and reported to the network side device for a plurality of times.