The invention provides a solution for dissolving chromate conversion coating of color-coating hot dip galvanizing base plate. The solute in solution comprises 0.01%-0.1% by wt of alkaline buffering agent and 0.01-0.1% by wt of zinc alkaline corrosion inhibitor. The solvent is distilled water. The alkaline buffering agent comprises di-sodium hydrogen phosphate, sodium hydroxide and one of potassium hydroxide or sodium bicarbonate. The zinc alkaline corrosion inhibitor comprises hexamethylene tetramine, sodium silicate and one of sodium dodecyl benzene sulfonate or sodium dodecyl sulfonate. The solution of invention can also comprises 0.001%-0.5% by wt of additive. The additive comprises sodium carbonate and one of cupferron or zinc oxide. Compared with prior technology, the invention solves reconstruction problem of hexavalent chromium in the dissolving process, avoids reducing of hexavalent chromium content, improves accuracy of measuring result; makes error of measuring result decrease by more than 80%, and possesses higher economical and social benefits.