Faced by issues in the mushroom cultivation, such as substrates shortage, high cost and large volume in direct air-dry or inconvenient long-distance transportation, silage ramie byproducts were tested for Pleurotus eryngii cultivation in this study. The effects of moisture, pH, calcium salts, sugars, additives, and carbonitride on the Pleurotus eryngii growth were measured from mycelial growth rate and biological efficiency. The optimal medium conditions of the silage ramie byproducts and mushroom residues for eryngii cultivation as well as the product quality were also determined. The results showed that the when the cultivation medium contained 50% silage ramie byproducts, 35% nitrogen source, 67.5% moisture content, 1% calcium carbonate and 1% sucrose with a 5.5 pH value, the biological efficiency of Pleurotus eryngii could reach up to 70% above; Compared with the cotton seed hulls medium cultivation, the protein content of the Pleurotus eryngii was increased by 30% and the total sugar and fat were reduced by 24% and 33%, respectively. This study demonstrated that the silage ramie byproduct should be a good raw material for Pleurotus eryngii cultivation.