Disclosed are a bipolar stack unit cell structure (1) and an all-solid secondary battery (2) including the same. The bipolar stack unit cell structure includes: a bicell (100) in which a first anode current collector (10), a first anode active material layer (20), a first electrolyte layer (30), a first cathode active material layer (40), a cathode current collector (50), a second cathode active material layer (40'), a second electrolyte layer (30'), a second anode active material layer (20'), and a second anode current collector (10') are sequentially arranged, wherein a plurality of the bicells (100) are stacked, and a compression pad (60) is provided between the first anode current collector (10) and second anode current collector (10') of adjacent bicells (100) of the plurality of bicells (100). The bipolar stack unit cell structure (1) absorbs a volume change of an anode and suppresses a volume change of the entire cell to obtain a stable lifespan, and the capacity and voltage thereof can be freely designed by bipolar connection of the unit cells.