A dynamic wheel load instrument with a simple and convenient structure is disclosed. A connecting section comprises a bending section and a bending section II, the lower part of the bending section Iand the lower part of the bending section II are stably arranged, and an included angle of 90 degrees is kept between the direction from one side part of the bending section I to the other side part of the bending section I and the direction from one side part of the bending section II to the other side part of the bending section II; the direction from one side part of the bending section I to the other side part of the bending section I is the first direction, the direction from one side part of the bending section II to the other side part of the bending section II is the second direction,and the 90-degree included angle is kept between the first direction and the second direction; one side of the bending section I is connected with a roller of a motor I in a linkage mode, and the other side of the bending section I is rotatably arranged on a supporting piece. The defect that in the prior art, the working period is shortened under the oversinking condition, so that the dynamic wheel load instrument is damaged due to brittle failure is effectively avoided.