Provided is a chromium-free, low-temperature curable, metal-surface treatment composition comprising 5 to 30 parts by weight of a silane compound having an epoxy group and a silane compound having an amino group or a hydrolytic condensate thereof; 0.1 to 5 parts by weight of a vanadium compound; 0.1 to 5 parts by weight of a magnesium compound; 1 to 10 parts by weight of organic/inorganic acids; 0.05 to 2 parts by weight of a crosslinking accelerating and coupling agent; 0.01 to 1 part by weight of an antifoaming agent; 1 to 2 parts by weight of a wetting agent; and the balance of water and ethanol, based on 100 parts by weight of the total solution. In addition, a steel sheet coated with the above-described metal-surface treatment composition is low-temperature curable and provides anticorrosiveness while containing no chromium components.