The invention discloses an electrolytic polishing solution of an invar alloy and an electrolytic polishing method. The electrolytic polishing solution of the invar alloy is characterized in that C3H8O2, HClO4 and C2H5OH are mixed according to the volume ratio of 1 to 2 to 17-22; the invar alloy sample is placed in the electrolytic polishing solution as an anode, and insoluble metal is used as a cathode; and the temperature of the electrolytic polishing solution is 0-10 DEG C, the polishing voltage is 30-40 V, and electrolytic polishing is carried out on an invar alloy sample. According to themethod, the polishing solution is simple to prepare and good in polishing effect, the surface of the sample is flat and smooth, no obvious deformation layer is generated, and the polishing solution can be used multiple times; the stress layer on the surface can be effectively removed, the electrolytic polishing quality is effectively improved, and the high-calibration rate electron diffraction pattern is obtained; the electrolytic polishing method can effectively remove the stress layer on the surface of the sample, the electrolytic polishing quality is effectively improved, and the strong diffraction pattern which is generated by the EBSD test is facilitated, so that the high-calibration rate can be obtained, and the research of microstructure of the crystal boundary characteristic, texture, stress strain and the like of the invar alloy is facilitated.