The utility model provides an assembled ballasted track bed lateral resistance testing device. The assembled ballasted track bed lateral resistance testing device comprises a top plate, two inclined arms, two hooks and a dial indicator, the top plate is used for being connected to the force application end of a force application device for applying transverse pushing force to a steel rail and provided with a connecting plate, and a first positioning hole is formed in the connecting plate. One end of each oblique arm is detachably connected with the connecting plate, and a second positioning hole is formed in the other end of each oblique arm; a clamping plate clamped in the first positioning hole or the second positioning hole is arranged on the side surface of one end of each hook, and the other end of each hook is a free end and is used for hanging an embedded iron seat; the dial indicator is used for being fixed to a sleeper, a probe of the dial indicator abuts against the rail, andthe dial indicator and the force application device are located on the two sides or the same side of the rail respectively. The assembled ballast track ballast bed lateral resistance testing device is convenient to use and carry, can be used for testing the ballast bed lateral resistance of single sleepers or double sleepers of different fastener types, and is accurate in testing and convenient to disassemble, assemble and carry.