Provided is a liquid mixture for filling blind holes in copper foil, relating to the technical field of electroplating hole filling. The liquid mixture comprises copper sulfate pentahydrate 210-240 g/L, citric acid 40-50 g/L, tartaric acid 10-20 g/L, chloride ion 40-70 ppm, accelerator 0.5-2 g/L, leveling agent 5-15 g/L, inhibitor 5-10 g/L, and sulfonate ion liquid 50-180 g/L. The leveling agent comprises tetranitro blue tetrazolium blue and triazolyl acetyl hydrazide.