Abstract: Damage-reduction seismic design is a practical design method of performance-based seismic design. According to damage mode of multi-ribbed slab structure which releases earthquake energy by stages, block-frame-outer frame, damagereduction design theory is applied to structure seismic design. It is illustrated that damage-reduction seismic design model and three-stage damage-reduction design of multi-ribbed slab structure. Block which acts as damage-reduction member is served as first damage-reduction fortification line, frame which acts as damage-reduction minor structure is served as second fortification line, and outer frame and reinforced measure are served as third fortification line.