The invention relates to a cross slid platform testing device of a steering frame, aiming at solving the defects of complicated structure, single test item, low degree of automation, high error of test data and the like of the existing test platform. The device mainly consists of a transverse actuator mechanism (A), a cross slid platform mechanism (B), a longitudinal actuator mechanism (C), a three dimensional force sensor (D) and a wheelset clamping device (E); the device is characterized in that the transverse actuator mechanism (A) and the longitudinal actuator mechanism (C) are arranged on the cross slid platform mechanism (B) in a crossing way; the cross slid platform mechanism (B) includes a middle slid platform narrow board (I) which is provided with four height-adjusting actuator mechanisms (II), an oil lever of each height-adjusting actuator mechanism (II)is fixed on the middle slid platform narrow board (I), and a piston rod (9) end thereof is connected with a cross rolling guide rail mechanism (III) positioned under the middle slid platform narrow board (I); the three dimensional force sensor (D) is arranged on the slid platform narrow board (I).