A power measurement apparatus includes a radio frequency input terminal, a measurement module, an interface, a memory, and a control unit. The radio frequency input terminal is connected to a radio frequency device. The measurement module is connected to the radio frequency input terminal to convert the radio frequency signal into a voltage signal. The interface is connected to the measurement module, receiving and transmitting the voltage signal from the measurement module. The memory is connected to the interface to store a voltage-power table related to the radio frequency signal. The control unit is connected to the interface to query the voltage-power table in the memory via the interface, and obtain the power of the radio frequency device according to the voltage signal output from the measurement module.