In one embodiment, a synchronous rectification control method can include: (i) setting or updating a count value when a rectification switch is turned on; (ii) generating an off enable signal after a delay time corresponding to the count value has elapsed; (iii) turning off the rectification switch based on the off enable signal, and comparing a drain-source voltage of the rectification switch against a reference voltage; and (iv) generating a comparison signal for updating the count value based on the drain-source voltage and the reference voltage.