The invention discloses a switching power supply, and a synchronous rectification control circuit and a control apparatus thereof, wherein the synchronous rectification control circuit comprises a regulating module, a discharge detection module, a charging detection module, an integral module and a logic module. according to the synchronous rectification control circuit, the adjustment resistor isretained to be connected to the reference ground, so that the synchronous rectification control circuit still has the characteristics of simple structure; accurate shielding time can be obtained by virtue of the adjusting module and integral module to ensure that no false triggering occurs; and the synchronous rectification control circuit, the regulating resistor and a synchronous rectifying tube equivalently constitute a two-port structure, and the topological structure of switching power supply is not limited, thereby facilitating flexible configuration of switching power supply circuit bya user conveniently.