Flat car with foldable trundle units

The invention discloses a flat car with foldable trundle units. The flat car comprises a bearing plate, a load-bearing supporting frame and trundle units. A trundle unit rotation driving device is further included. The trundle unit rotation driving device comprises an operating handle, a connecting rod, a front linkage mechanism and a rear linkage mechanism. The operating handle is pivoted with abearing plate and can rotate around the pivoting axis of the operating handle; when the operating handle is rotated from the first position to the second position, the operating handle can be linked with the front linkage mechanism and the rear linkage mechanism through the connecting rod to respectively drive a front trundle unit and a rear trundle unit to rotate from the folding storage positionto the unfolding rolling position; the front trundle unit and the rear trundle unit are each provided with a reset device, and when the operating handle rotates to the first position from the secondposition, the front trundle