A resonant power converter, comprising: an inverter branch, a resonant branch connected to the inverter branch, a transformer connected to the resonant branch, and a rectification and filtering branch connected to the transformer, wherein a primary side of the transformer is connected to the resonant branch, a secondary side of the transformer is connected to the rectification and filtering branch, and the resonant power converter further comprises: a detection branch connected to both the secondary side of the transformer and the rectification and filtering branch, a determining branch connected to the detection branch, and a control branch connected to both the determining branch and the inverter branch, wherein the detection branch is configured to: obtain a secondary current of the transformer, generate, according to the secondary current, a pulse signal corresponding to the secondary current, and send the pulse signal corresponding to the secondary current to the determining branch; the control branch is configured to generate a drive signal and send the drive signal to the inverter branch and the determining branch, wherein the drive signal is used to drive the inverter branch; the determining branch is configured to: receive the pulse signal that is corresponding to the secondary current and sent by the detection branch and the drive signal that is sent by the control branch, and generate first information and send the first information to the control branch according to the pulse signal corresponding to the secondary current and the drive signal, wherein the first information is used to indicate a resonant status of the resonant power converter; and the control branch is further configured to: receive the first information sent by the determining branch, and control frequency of the drive signal according to the first information; wherein the determining branch is configured to: determine that a rising edge of the pulse signal corresponding to the secondary current and a rising edge of the drive signal are synchronous and that a falling edge of the pulse signal corresponding to the secondary current and a falling edge of the drive signal are synchronous; and generate the first information, wherein the first information is used to indicate that the resonant power converter works at a resonant frequency point; and wherein the control branch is further configured to keep the frequency of the drive signal unchanged according to the first information. the detection branch is configured to: obtain a secondary current of the transformer, generate, according to the secondary current, a pulse signal corresponding to the secondary current, and send the pulse signal corresponding to the secondary current to the determining branch; the control branch is configured to generate a drive signal and send the drive signal to the inverter branch and the determining branch, wherein the drive signal is used to drive the inverter branch; the determining branch is configured to: receive the pulse signal that is corresponding to the secondary current and sent by the detection branch and the drive signal that is sent by the control branch, and generate first information and send the first information to the control branch according to the pulse signal corresponding to the secondary current and the drive signal, wherein the first information is used to indicate a resonant status of the resonant power converter; and the control branch is further configured to: receive the first information sent by the determining branch, and control frequency of the drive signal according to the first information; wherein the determining branch is configured to: determine that a rising edge of the pulse signal corresponding to the secondary current and a rising edge of the drive signal are synchronous and that a falling edge of the pulse signal corresponding to the secondary current and a falling edge of the drive signal are synchronous; and generate the first information, wherein the first information is used to indicate that the resonant power converter works at a resonant frequency point; and wherein the control branch is further configured to keep the frequency of the drive signal unchanged according to the first information. determine that a rising edge of the pulse signal corresponding to the secondary current and a rising edge of the drive signal are synchronous and that a falling edge of the pulse signal corresponding to the secondary current and a falling edge of the drive signal are synchronous; and generate the first information, wherein the first information is used to indicate that the resonant power converter works at a resonant frequency point; and wherein the control branch is further configured to keep the frequency of the drive signal unchanged according to the first information.