A method for beam failure recovery in a wireless communication system is provided. The wireless communication system includes a UE and a base station. The method includes the following actions. A first BWP configuration, a second BWP configuration and a BWP inactivity timer are received by the UE from the base station. The UE is configured to be switched from a first BWP to a second BWP when the BWP inactivity timer expires, and the first BWP corresponds to the first BWP configuration and the second BWP corresponds to the second BWP configuration. Whether a beam failure recovery procedure is triggered is determined by the UE. The BWP inactivity timer is stopped by the UE when the beam failure recovery procedure is triggered.