Hydraulic bi-directional lock

The utility model discloses a hydraulic bi-directional lock, which comprises a valve body (1), a valve seat (2), a valve housing (4) and a valve core (10), wherein, a cylindrical cavity is formed in the valve body (1); two liquid inlets PA and PB as well as two liquid outlets A and B are formed respectively on two opposite surfaces vertical to the cylindrical cavity and are communicated with the cylindrical cavity separately; a piston (5) is installed at the inner center of the cylindrical cavity; the valve housing (4), a first layer gasket (3), the valve seat (2), an end surface seal ring (9), a second layer gasket (8), the valve core (10), a valve core spring (7) and a connector (6) are symmetrically installed in turn on the left and the right sides of the piston (5); and a step is processed in a position right opposite to the circumferential hole of the valve housing (4) at one end on the valve core (10) which is close to the piston (5). Due to the structure of the utility model, the valve can develop some