A vehicular torsion bar suspension device, which comprises a front torsion bar spring and a rear torsion bar spring respectively installed at front and rear suspensions of the vehicle. The opposite ends of the front and rear torsion bar springs on the same side are connected mutually by a connection mechanism, and are connected with a vehicle frame through a positioning device. The connection mechanism is mounted between the front and rear torsion bar springs on the same side, so that a linkage relationship is established between the front and rear torsion bar springs. The device improves the vibration situation of the vehicle when driving the vehicle on an uneven ground, and prevents the vehicle frame and vehicle body skeleton from suffering torsional force. As a result, the usage life of the vehicle is prolonged.