Embodiments of the disclosure provide a physical layer collision avoidance (PLCA) device and a method for performing emergency transmission thereof. The method includes: in response to determining that the PLCA device enters an emergency transmission mode, finding a first PLCA device that is performing a corresponding first packet transmission; in response to determining that a first transmission priority of the first PLCA device is lower than a transmission priority of the PLCA device, suspending the first packet transmission of the first PLCA device; and in response to determining that it is the PLCA device's turn to perform a corresponding packet transmission, sending an emergency packet corresponding to the emergency transmission mode.