A communication device for handling a physical uplink (UL) control channel (PUCCH) collision, comprises at least one storage device; and at least one processing circuit, coupled to the at least one storage device. The at least one storage device stores instructions, and the at least one processing circuit is configured to execute the instructions of transmitting a first PUCCH in at least one first physical resource block (PRB) of at least one first slot to a network; dropping a second PUCCH in at least one second PRB of at least one second slot, wherein the at least one second slot is overlapped with the at least one first slot; and transmitting the second PUCCH in at least one third PRB of at least one third slot to the network, wherein the at least one third slot is after the at least one first slot.