The invention relates to a large-headroom restorable-function steel-framed eccentrically-braced system and belongs to the field of structural engineering. The large-headroom restorable-function steel-framed eccentrically-braced system comprises two welded combination special-shaped columns, two I-beam segments having an oblique support bar, two Y-shaped diagonal braces, one energy-dissipating beamsegment and a plurality of connection devices. All the components of the system herein are processed in a factory; the precision and quality are easier to control; connecting and mounting are formedin situ completely through high-strength bolts, so that quick assembly is easy to implement; beam-column joints are specially treated, a cover plate can buckle to dissipate energy, excessive deformation of the cover plate can also be limited, joint bearing capacity is more stable, and more energy can be dissipated; the design idea of the energy-dissipating beam segment and eccentric bracing is introduced, so that structural 'fuse' effect is achieved; brace size and shape are changed, a door opening can be set in the position where bracing is provided, so that steel consumption is lowered, andeconomic benefit and applicability are improved.