The invention relates to agaricus blazei murrill compost and a cultivation method thereof, and belongs to the technical field of edible mushroom cultivation. The agaricus blazei murrill compost is prepared from, by weight, 80-90 parts of water hyacinth dry feed, 4-9 parts of agaricus blazei murrill rape seed cake, 1-3 parts of urea, 1-3 parts of calcium superphosphate and 2-4 parts of hydrated lime. The method for utilizing the agaricus blazei murrill compost to cultivate agaricus blazei murrill mainly comprises the steps of building a pile, turning the pile, conducting secondary fermentation,building a mushroom greenhouse, conducting sowing and field planting, fruiting and the like. The agaricus blazei murrill compost with water hyacinth being a main raw material is adopted, the problemsof environmental pollution caused by stacking of water hyacinth waste and inadequate water conservation which exists in agaricus blazei murrill compost in the prior art are also solved, the production cost of agaricus blazei murrill is lowered, a scientific cultivation method is adopted, and the yield of agaricus blazei murrill is increased.