The invention discloses a grate cooler with a built-in cooling turning wheel and high heat exchange efficiency. The grate cooler comprises a kiln head cover, an outer shell, a high temperature air outlet, a low temperature air outlet, a cement clinker outlet, grate plates, a fan, an air supply pipeline, a rotary kiln and the cooling turning wheel. The cooling turning wheel is mounted in the gratecooler. The air supply pipeline is mounted in the middle of a front wall of the grate cooler. The invention further discloses a structure of the cooling wheel. The cooling wheel comprises a turning wheel body, a sealing bearing and a rotary shaft. A cooling medium flow channel is formed in the turning wheel body. According to the grate cooler and a device which are disclosed by the invention, mostof clinkers fall onto the turning wheel from the rotary kiln and are sprinkled to the secondary grate plate, a small part of clinkers fall on the grate plate on the front section only, thus, the small part of a clinker layer is thinned, cold air can pass and cool the clinkers advantageously, in addition, through disturbance of the turning wheel, massive cement clinkers are not liable to be formed, stacking of the clinkers in the area can be effectively prevented, and the phenomenon of snowman piling is eliminated.