Abstract: A heating loop protective circuit, a respiration heating circuit and respiration aiding equipment are provided, wherein the heating loop protective circuit is connected to a heating loop and includes an acquisition sub-circuit, a suppression sub-circuit, a protective sub-circuit and a discharge sub-circuit; the acquisition sub-circuit collects input voltage of the protective sub-circuit and sends the input voltage to the suppression sub-circuit; the suppression sub-circuit clamps the input voltage and releases current through the discharge sub-circuit; and the protective sub-circuit performs short-circuit protection when the current is too high. In the present disclosure, the over-voltage protection is realized through the voltage clamp in such a manner of monitoring the voltage of the heating loop and suppressing the input voltage through the suppression sub-circuit, and then the over-current protection is realized through the protective sub-circuit when the circuit current is too high.