The invention discloses a single-tube resonance soft switch circuit of an induction cooker and a control method thereof. The single-tube resonance soft switch circuit of the induction cooker comprises a rectifier and filter circuit, a main resonance circuit and an auxiliary resonance circuit, wherein the main resonance circuit comprises a heating winding disc, a resonance capacitor and a main switching tube, the auxiliary resonance circuit comprises an auxiliary resonance inductor and an auxiliary switch, and a main circuit of the auxiliary resonance circuit is connected with the main switching tube in parallel. When the single-tube resonance soft switch circuit of the induction cooker is in a low-power output sate and the voltage of a collector of the main switching tube cannot be subjected to normal resonance to reach zero, the auxiliary resonance circuit begins working to release residual electric energy of the resonance capacitor before the main switching tube is switched on. According to the invention, the zero-voltage-switching of the main switching tube can be realized in a low-power output state and real low-power continuous output can be reached, so that the performance and reliability of the induction cooker are improved.