The invention discloses a solid oxide electrolysis cell electrochemical performance test system, which comprises a hydrogen electrode chamber, a ceramic ring and a three-in-one electrode. A glass sealing ring is arranged between the three-in-one electrode and the top of the hydrogen electrode chamber. The bottom of the hydrogen electrode chamber is provided with a flange plate. The hydrogen electrode chamber and the flange plate are integrated as a whole. The flange plate is provided with an air inlet pipe and an air outlet pipe. The air inlet pipe and the air outlet pipe and the flange plate are integrated and the material is silicon carbide ceramics. Several cooling fins are arranged on the pipe wall at the lower end of the air inlet pipe and the air outlet pipe. A hydrogen electrode wiring tube penetrates through the middle of the flange plate. The middle part of the hydrogen electrode wiring tube is provided with a hydrogen electrode wire, the top of which is contacted with a hydrogen electrode on the three-in-one electrode. An oxygen electrode at the upper end of the three-in-one electrode is connected to an oxygen electrode wire. The test system is simple to install, has high gas tightness, and can effectively raise safety and accuracy of a high temperature oxide electrolysis cell test.