The invention discloses a leakage protector with a phase line switching function, which comprises a current transformer and a three-phase current detection circuit. The current transformer is used for detecting leakage current and outputting a leakage signal. The output end of the current transformer is connected with an amplifying circuit, and the amplifying circuit amplifies the leakage signal and inputs the signal into a single chip. The current detection circuit is connected with a current signal receiving circuit, a three-phase current signal receiving circuit inputs a current signal into the single chip, the current signal receiving circuit is used for receiving a three-phase current signal, the output end of the single chip is connected with a driving circuit in driving connection with a switch in a three-phase line, the driving circuit is connected with the input end of the single chip through a feedback circuit, the feedback circuit inputs a driving signal of the driving circuit into the single chip. The leakage protector with the phase line switching function can perform automatic switching according to the load situation between three phases so as to balance current among the three phases, reduces the harm caused by imbalance of the current among the three phases, enables a power grid to be operated stably, and improves power supply quality.