The present invention provides a metal surface treatment liquid with which it is possible to obtain a surface-treated metal material having excellent corrosion resistance, processing resistance, chemical resistance, coating film adhesiveness, and post-coating corrosion resistance. This metal surface treatment liquid has an isocyanate group blocked by a blocking agent, and includes a blocked isocyanate (A) having an isocyanurate structure and a polyalkyleneoxy chain, and an organic resin (B) having at least one type of functional group selected from the group consisting of hydroxy groups, amino groups, sulfo groups, and carboxy groups.
