An automatic split phase crossing system for electrified railway section posts, comprising: pantograph identifiers (P1, P2, P3) for sensing a traveling position and direction of a train; a voltage transformer for detecting voltage of a first power supply arm; a first resistor and a first thyristor switch, which are connected to two ends of a first sectionalizer in parallel respectively, wherein the first sectionalizer is between the first power supply arm and a neutral section; a second resistor and a second thyristor switch, which are connected to two ends of a second sectionalizer in parallel respectively, wherein the second sectionalizer is between the neutral section and a second power supply arm; and a control unit for executing the following operations: in the event that the train travels from the first power supply arm to the first sectionalizer, controlling the first thyristor switch to be turned on during voltage zero-crossing of the first power supply arm; in the event that the train travels from the first power supply arm into the neutral section via the first sectionalizer, controlling the first thyristor switch to be turned off with current zero-crossing of the first thyristor switch for the time being, and simultaneously controlling the second thyristor switch to be turned on; and in the event that the train travels from the neutral section into the second power supply arm via the second sectionalizer, controlling the second thyristor switch to be turned off. pantograph identifiers (P1, P2, P3) for sensing a traveling position and direction of a train; a voltage transformer for detecting voltage of a first power supply arm; a first resistor and a first thyristor switch, which are connected to two ends of a first sectionalizer in parallel respectively, wherein the first sectionalizer is between the first power supply arm and a neutral section; a second resistor and a second thyristor switch, which are connected to two ends of a second sectionalizer in parallel respectively, wherein the second sectionalizer is between the neutral section and a second power supply arm; and a control unit for executing the following operations: in the event that the train travels from the first power supply arm to the first sectionalizer, controlling the first thyristor switch to be turned on during voltage zero-crossing of the first power supply arm; in the event that the train travels from the first power supply arm into the neutral section via the first sectionalizer, controlling the first thyristor switch to be turned off with current zero-crossing of the first thyristor switch for the time being, and simultaneously controlling the second thyristor switch to be turned on; and in the event that the train travels from the neutral section into the second power supply arm via the second sectionalizer, controlling the second thyristor switch to be turned off. in the event that the train travels from the first power supply arm to the first sectionalizer, controlling the first thyristor switch to be turned on during voltage zero-crossing of the first power supply arm; in the event that the train travels from the first power supply arm into the neutral section via the first sectionalizer, controlling the first thyristor switch to be turned off with current zero-crossing of the first thyristor switch for the time being, and simultaneously controlling the second thyristor switch to be turned on; and in the event that the train travels from the neutral section into the second power supply arm via the second sectionalizer, controlling the second thyristor switch to be turned off.