The invention discloses a non-contact yarn vibration frequency detection circuit which comprises a signal collection circuit, an AC in-phase amplification circuit, a high-pass filter circuit, a signalconditioning circuit, a ninth resistor R9, a tenth resistor R10 and a digital signal output end; the signal collection circuit, the AC in-phase amplification circuit, the high-pass filter circuit andthe signal conditioning circuit are connected successively; and one end of the ninth resistor R9 is connected with the signal conditioning circuit, the other end of the ninth resistor R9 is connectedwith one end of the tenth resistor R10 and the digital signal output end, and the other end of the tenth resistor R10 is grounded.