The invention discloses a portable relay performance tester special for an electric system. The tester comprises a relay tester body, wherein the relay tester body comprises a shell and two test ends,and one side of the shell is provided with an oxidation layer removal device. The oxidation layer removal device is added to the relay performance tester body, when an oxidation layer appears on themetal tip test point of each test end, a polishing device does not need to be additionally searched, a polishing block can be driven to rotate through a gearbox only by shaking a handle so as to polish the metal tip test point of each test end, so that the oxidation layer attached to the metal tip test point of each test end can be quickly removed, the contact resistance of the metal tip test point of each test end and a tested element can be lowered, and test accuracy is improved.