The invention discloses an SVG split-phase control device and protection method based on serial optical fiber protection. According to the solved technical problem, SVG is protected in a timely and effective manner. The SVG split-phase control device based on serial optical fiber protection, which is provided by the invention, is provided with a main control board and a power module. According tothe main control board, a protection optical fiber is connected with a power module through a split-phase control optical fiber board and then the main control board. The SVG split-phase protection method based on serial optical fiber protection, which is provided by the invention, comprises the steps that the main control board sends out protection signals cyclically, and the signals are transmitted by the serial protection optical fiber; the protection signals are transmitted to the power module through the split-phase control optical fiber board, and then return to the main control board within a set time; and the main control board judges that the split-phase control optical fiber board and the power module work normally. Compared with the prior art, the device and method, which are provided by the invention, have the advantage that if a split-phase control optical fiber board or a power module fails, the power module is under latch-up protection to ensure that an SVG device is notdamaged and avoid greater losses caused by the expansion of the fault.