The invention discloses a moving object sensor. The moving object sensor comprises a circuit board, a shielding cover and a drawing type capacitor and is characterized in that the drawing type capacitor comprises high-frequency capacitive couplers formed by copper foil on the circuit board, and a moving object detecting signal is fed through the high-frequency capacitive couplers; the capacitive couplers include two non-symmetrical plate capacitors Ct and Cr, each of the Ct and Cr comprises a signal transmitting unit, a signal receiving unit and a mixer, the Ct feeds the high frequency signalof a signal generating unit to a transmission antenna, the Cr inputs the high-frequency signal into the mixer through a receiving antenna, the moving object sensing signal is output from the bottom ofthe mixer, the signal generating unit is connected with the transmitting unit and the mixer, the mixer is in output connection with the receiving unit and the sensing signal, and the signal generating unit is connected with a power circuit. High-frequency signal input and output are completed by using the two capacitive couplers, high sensing sensitivity is achieved, and long-distance moving object sensing is achieved.