A wireless detection apparatus includes an antenna, a voltage control oscillator, and a processing unit. The antenna receives a first wireless signal and generates an electrical signal according to the first wireless signal. The first wireless signal is generated by reflecting a second wireless signal from an object under test. The voltage control oscillator is coupled to the antenna to generate an oscillating signal under an interference of the electrical signal. The oscillating signal varies with variation of the electrical signal. The processing unit is coupled to the voltage control oscillator to evaluate a parameter of the object under test according to the variation of the oscillating signal.