A method for preparing biological feed by using waste edible mushroom rods as raw material comprises the following specific steps: selecting and mixing the waste edible mushroom rods and one or more of rich-resource and low-price rural crop straws such as rice straws, wheat straws, corn straws, peanut vines, sweet potato vines, soybean straws, non-toxic weeds and broadleaf leaves, as main raw materials; blending with a small amout of concentrate material; fermenting through high-quality probiotic, namely EM, to obtain the final low-cost biological feed. Through the implementation of the method, the main raw materials, namely the waste edible mushroom rods and the crop straws, are very wide in sources, easy to collect and low in cost; besides, the waste edible mushroom rods also contain plenty of mycelia, while the mycelia contain rich protein and various amino acids; through improvement and conversion, the waste edible mushroom rods and the crop straws are prepared into comprehensive-nutrition palatable low-cost feed which can be directly absorbed by animals.