The invention relates to a viscous plastic hinge comprising an energy consumption unit, a limiting unit and a connecting assembly. The energy consumption unit is a cylinder and internally provided with a rotating shaft, a partition plate, a rotating plate and viscous liquid. The limiting unit consists of a limiting pin, a limiting plate and a left connecting plate. The connecting assembly includesconnecting plates and anchor plates. The rotating shaft, the rotating plate, the left connecting plate and the left anchoring plate form the left part of the viscous plastic hinge, and a cylindricalbox body, the partition plate, the limiting plate, the right connecting plate and the right anchoring plate form the right part of the viscous plastic hinge, after the limiting pin is cut off, the left part and right part can rotate relatively to each other. During normal use and small earthquakes, the limiting unit provides rotational rigidity, and the viscous plastic hinge is a rigid node. Whenmoderate and large earthquakes occur, the limiting pin is cut off, and the plastic hinge rotates relatively. When the rotating plate with a through hole rotates with the rotating shaft, the viscous liquid is forced to generate a certain flow velocity through the through hole in a short period of time to consume energy.