The present invention discloses a synchronous rectification type battery charging circuit, comprising: a charging main circuit for charging a battery; an anti-reflection switch tube, connected between a voltage input of the synchronous rectification type battery charging circuit and the charging main circuit; and a control logic and driving circuit, for controlling turning-on and cutting-off of the charging main circuit and the anti-reflection switch tube, characterized in that the synchronous rectification type battery charging circuit further including a protection circuit which outputs to the control logic and driving circuit an indicating signal for representing turning-on or cutting-off of the charging main circuit and the anti-reflection switch tube, according to a value of an input voltage of the synchronous rectification type battery charging circuit.