A control method for a series resonant converter, comprising: acquiring a feedback signal by collecting an analog output signal of the series resonant converter, and changing an operating frequency of the series resonant converter according to the feedback signal; and selecting a control mode of the series resonant converter according to a load condition, wherein the series resonant converter adopts a hybrid control mode when lightly loaded or unloaded and a frequency modulation control mode when heavily loaded, wherein a switching can be conducted between the hybrid control mode and the frequency modulation control mode through hysteresis control, and the hybrid control mode uses frequency and width modulation or width-fixed frequency modulation according to the operating frequency; wherein the method further comprises: setting a frequency modulation state flag bit, presetting a switching frequency corresponding to the frequency modulation state flag bit, comparing the operating frequency with a preset switching frequency, and determining the control mode of the series resonant converter according to a result of the comparison; wherein the frequency modulation state flag bit is 0 or 1, when the frequency modulation state flag bit is 0, the preset switching frequency is a first switching frequency, if the operating frequency of the series resonant converter is greater than the first switching frequency, the series resonant converter is determined to be lightly loaded or unloaded and adopts the hybrid control mode, otherwise, the frequency modulation state flag bit is set to 1 so that the series resonant converter enters the frequency modulation control mode; when the frequency modulation state flag bit is 1, the preset switching frequency is a second switching frequency higher than the first switching frequency, if the operating frequency of the series resonant converter is smaller than the second switching frequency, the series resonant converter is determined to be heavily loaded and adopts the frequency modulation control mode, otherwise, the frequency modulation state flag bit is set to 0 so that the series resonant converter enters the hybrid control mode. acquiring a feedback signal by collecting an analog output signal of the series resonant converter, and changing an operating frequency of the series resonant converter according to the feedback signal; and selecting a control mode of the series resonant converter according to a load condition, wherein the series resonant converter adopts a hybrid control mode when lightly loaded or unloaded and a frequency modulation control mode when heavily loaded, wherein a switching can be conducted between the hybrid control mode and the frequency modulation control mode through hysteresis control, and the hybrid control mode uses frequency and width modulation or width-fixed frequency modulation according to the operating frequency; wherein the method further comprises: setting a frequency modulation state flag bit, presetting a switching frequency corresponding to the frequency modulation state flag bit, comparing the operating frequency with a preset switching frequency, and determining the control mode of the series resonant converter according to a result of the comparison; wherein the frequency modulation state flag bit is 0 or 1, when the frequency modulation state flag bit is 0, the preset switching frequency is a first switching frequency, if the operating frequency of the series resonant converter is greater than the first switching frequency, the series resonant converter is determined to be lightly loaded or unloaded and adopts the hybrid control mode, otherwise, the frequency modulation state flag bit is set to 1 so that the series resonant converter enters the frequency modulation control mode; when the frequency modulation state flag bit is 1, the preset switching frequency is a second switching frequency higher than the first switching frequency, if the operating frequency of the series resonant converter is smaller than the second switching frequency, the series resonant converter is determined to be heavily loaded and adopts the frequency modulation control mode, otherwise, the frequency modulation state flag bit is set to 0 so that the series resonant converter enters the hybrid control mode.