The utility model provides a novel horizontal earthquake ditch slidable apron device, place on horizontal earthquake ditch -water planomural (6) and minor face L female cap board (1) down including long limit, long limit is spread and is pasted on the long limit of L female cap board and minor face L shape waterproof board (3) up, install the ascending mounting groove of notch (4) on building lateral wall (8) through staple (5), set up and install lower arcs of recesses PLASTIC LAMINATED (2) on horizontal earthquake ditch lateral wall (7) and building lateral wall (8) respectively through the staple in L female cap board below and both ends, the downward insert the installation inslot of minor face of L female cap board is installed on the building lateral wall through staple and mounting groove in the lump, and L shape waterproof board minor face up adopts adhesive material or cement mortar to bond on the building lateral wall. The utility model discloses simple structure, easy manufacturing, construction safety, anti -seismic performance and waterproof fireproof are effectual.