The invention relates to a double-six-degree-of-freedom motion test platform for a railway vehicle. The double-six-degree-of-freedom motion test platform comprises two six-degree-of-freedom motion test platforms of the same structure. Each six-degree-of-freedom motion test platform consists of a motion platform, a transverse force application unit, a longitudinal force application unit, a verticalforce application unit, a double-air bag lifter, and a card installation test unit. The transverse force application unit, the longitudinal force application unit, the vertical force application unitand the double-air bag lifter are rotationally connected to the motion platform. The card installation test unit is fixed on the upper surface of the motion platform and is symmetrically arranged. Anactuator is directly fixed on the supporting surface of a corresponding movable supporting seat. The transverse force is eliminated through constraining the actuator. The oil inlet/outlet of the oilcylinder of the actuator is connected with a power source pipeline. The card installation test unit is composed of a three-dimensional force measuring platform and a fixture, and the fixture is fixedly connected to the upper surface of the three-dimensional force measuring platform through bolts. According to the invention, the longitudinal, transverse, radial, revolution and lateroversion stiffness of a railway vehicle bogie can be tested. Meanwhile, the abrasion of a piston rod and the abrasion of the oil cylinder are reduced and the service life is prolonged. The measurement precision is high, and the error is reduced. The double-six-degree-of-freedom motion test platform is high in automation degree, and simple and convenient in test.