The disclosure provides an ultrasonic signal detection circuit including a sensing circuit, a unidirectional conduction circuit and a source follower circuit. The sensing circuit is connected to an input terminal of the source follower circuit through the unidirectional conduction circuit; the sensing circuit is configured to generate a piezoelectric signal according to a received ultrasonic echo signal and output the piezoelectric signal to the unidirectional conduction circuit. The piezoelectric signal is an alternating current signal; the unidirectional conduction circuit is configured to rectify the alternating current signal to only allow a forward or a reverse current portion thereof to pass through. The forward/reverse current portion charges/discharges the input terminal of the source follower circuit after passing through the unidirectional conduction circuit. The source follower circuit is configured to generate a detection signal according to a voltage at its input terminal and output the detection signal through its output terminal.