Methanol-concentrated wastewater is chosen to optimize the conditions of imbedded immobilization of microorganisms through a series of experiments. Activated sludge is imbedded in some little balls with the imbedding materials of Sodium Alginate and PVA, then orthogonal experiments of methanol wastewater treatments are done based on the decomposition of the indicator of COD. Whereafter, the optimum imbedding conditions of Sodium Alginate and PVA are determined and the performance of immobilized ball is improved under those conditions. Meanwhile, the study analyses the performance of the ball based on such parameters as the specific surface area, penetrability and electronic-microscope photo. It is concluded that reaction time is the most important factor, both SA and PVA are reticulations and their structures are suitable to grow for microorganisms, and the mechanical performance of the PVA immobilized ball is improved to a large scale after adding some chemicals.