Method and terminal for measuring and reporting power headroom

A method for measuring power headroom includes: when a user terminal transmits uplink physical channels on the subframe i, the component carrier group j, the user terminal measures the power headroom on the subframe i, the component carrier group j; wherein, the uplink physical channel is a Physical Uplink Shared CHannel (PUSCH) and/or a Physical Uplink Control CHannel (PUCCH), and the component carrier group j includes one or more component carriers. A method for reporting power headroom includes: the user terminal reports the power headroom to a base station, and indicates the component carrier or the component carrier group to which the reported power headroom belongs. The present invention also provides a terminal. The present invention enhances the timeliness for reporting the power headroom.