The invention relates to track bed grass lawn and a planting method thereof, belongs to the technical field of planting of track bed grass lawn. The track bed grass lawn comprises a grass lawn layer and a planting base material layer which are arranged inside a track bed area, wherein the planting base material layer is laid below the grass lawn layer; a drainage layer is laid below the planting base material layer; a filtering layer is arranged between the planting base material layer and the drainage layer; the planting base material layer comprises the following mixed components: 20%-30% of organic matters, 40%-50% of garden soil, 15%-20% of coarse sand and 30-50 g/m<2> of a water-retaining agent; the soil particle diameter of the planting base material layer is smaller than or equal to 3 cm. According to the track bed grass lawn and the planting method thereof, the grass lawn is planted on the track bed, and the method for planting the grass lawn on the track bed comprises the following steps: A, laying the drainage layer and a sprinkling irrigation pipeline; B, further laying the filtering layer; C, spreading the planting base material layer; D, laying the grass lawn layer; E, managing the grass lawn; the steps are the embodiment of a great challenge to the existing grass planting technology, meanwhile, the internal structure of the traditional track bed can be optimized, the surrounding environment of the track can be beautified and improved, and the track bed can be turned into a picture of beautiful scenery and better integrated into the city environment.