The utility model provides a horizontal wheel assembly for a quay crane bracket trolley. The horizontal wheel assembly comprises a wheel body, a bearing and a wheel shaft, wherein the wheel shaft comprises a shaft body and a positioning shaft shoulder; the bearing is mounted on the wheel shaft; the wheel body is mounted on the bearing; the positioning shaft shoulder is arranged on the outer sides of the wheel body and the bearing; a spacing sleeve is arranged between the positioning shaft shoulder and the wheel body, and comprises a shaft hole, a spacing part and an end cover part; the spacing part is propped against the outer end surface of the bearing; the end cover part is propped against the outer end surface of the wheel body; the pore diameter of the shaft hole is smaller than the diameter of the positioning shaft shoulder. The utility model further provides the quay crane bracket trolley. The quay crane bracket trolley comprises a base and horizontal wheels arranged at the four corners of the base; the horizontal wheels are connected onto the base through the wheel assemblies for the quay crane bracket trolley. According to the utility model, the horizontal wheel assembly adopt less movable parts are less, and is not easy to get loose, so that risks that people is injured by objects falling from high altitudes, and the bracket trolley goes off track and derails are reduced; potential safety hazards are completely eradicated effectively.