The present invention provides a method for improving the filtration rate of a high-silicon-cobalt raw material dissolving solution. The method is characterized by comprising: (1) dissolving a cobalt raw material with sulfuric acid, and adding an oxidizing agent or reducing agent to the cobalt raw material dissolving solution to adjust the mass ratio of Fe<3+> to Si in the cobalt raw material dissolving solution to 1:1-3; and (2) adjusting the temperature of the cobalt raw material dissolving solution to 50-70 DEG C, adjusting the final pH value to 3.0-3.5, stirring, and filtering. According to the present invention, the ratio of Fe<3+> to Si is adjusted and the PH value is adjusted, such that the Fe<3+> in the solution is hydrolyzed to generate a Fe(OH)3 colloid, the Fe(OH)3 colloid and a negatively-charged silica gel colloidal are subjected to interaction coagulation to generate large volume floc, and the large volume floc is easy to remove during the filtering, wherein the filtration rate can achieve 0.2-0.5 m<3>m<-2>h<-1>.