A vehicle body tilting device for a railway vehicle, comprising: a telescopic hydraulic actuator interposed between a vehicle body and a bogie of the railway vehicle and comprising a cylinder, a piston housed in the cylinder to be free to slide, a piston rod that is joined to the piston and projects outward from the cylinder, and two pressure chambers (R1, R2) defined in the cylinder by the piston, an actuator circuit that drives the hydraulic actuator to elongate and contract; and a damping and locking circuit that damps elongation/contraction of the hydraulic actuator caused by an external force and includes a shutoff mechanism (17, 18, 19, 43) that shuts off a flow of working fluid accompanying the elongation/contraction of the hydraulic actuator caused by the external force, the damping and locking circuit comprising a flow passage (14a, 14b, 14c, 14d, 14e, 26) that connects the two pressure chambers (R1, R2), a shutoff valve (16, 43) that shuts off a predetermined direction flow of the flow passage (14a, 14b, 14c, 14d, 14e, 26) when operated, and a damping force generating element (15, 15b, 27) that applies a resistance to fluid flowing through the shutoff valve (16, 43) in an open state, characterized in that the shutoff valve (16, 43) comprises a valve seat, a valve body that sits on the valve seat, a spring that biases the valve body toward the valve seat, and a back pressure chamber that applies a back pressure to the valve body, the valve body is configured to shut off the flow of working fluid through the flow passage (14a, 14b, 14c, 14d, 14e, 26) when seated on the valve seat and separate from the valve seat, when the back pressure in the back pressure chamber is released, in accordance with a pressure in a high pressure side pressure chamber of the two pressure chambers (R1, R2) to allow working fluid to flow through the flow passage (14a, 14b, 14c, 14d, 14e, 26), and the shutoff mechanism (17, 18, 19, 43) comprises a drain passage that releases the back pressure in the back pressure chamber, and a solenoid switch valve (18, 19) that shuts off the drain passage. a telescopic hydraulic actuator interposed between a vehicle body and a bogie of the railway vehicle and comprising a cylinder, a piston housed in the cylinder to be free to slide, a piston rod that is joined to the piston and projects outward from the cylinder, and two pressure chambers (R1, R2) defined in the cylinder by the piston, an actuator circuit that drives the hydraulic actuator to elongate and contract; and a damping and locking circuit that damps elongation/contraction of the hydraulic actuator caused by an external force and includes a shutoff mechanism (17, 18, 19, 43) that shuts off a flow of working fluid accompanying the elongation/contraction of the hydraulic actuator caused by the external force, the damping and locking circuit comprising a flow passage (14a, 14b, 14c, 14d, 14e, 26) that connects the two pressure chambers (R1, R2), a shutoff valve (16, 43) that shuts off a predetermined direction flow of the flow passage (14a, 14b, 14c, 14d, 14e, 26) when operated, and a damping force generating element (15, 15b, 27) that applies a resistance to fluid flowing through the shutoff valve (16, 43) in an open state, characterized in that the shutoff valve (16, 43) comprises a valve seat, a valve body that sits on the valve seat, a spring that biases the valve body toward the valve seat, and a back pressure chamber that applies a back pressure to the valve body, the valve body is configured to shut off the flow of working fluid through the flow passage (14a, 14b, 14c, 14d, 14e, 26) when seated on the valve seat and separate from the valve seat, when the back pressure in the back pressure chamber is released, in accordance with a pressure in a high pressure side pressure chamber of the two pressure chambers (R1, R2) to allow working fluid to flow through the flow passage (14a, 14b, 14c, 14d, 14e, 26), and the shutoff mechanism (17, 18, 19, 43) comprises a drain passage that releases the back pressure in the back pressure chamber, and a solenoid switch valve (18, 19) that shuts off the drain passage.