Two issues in coprecipitation route to synthesize Bi-Pb-Sr-Ca-Cu-O Superconductor precursor powder,coprecipitation mode and coprecipitation medium, which are a first priority, are analysized based on thermodynamicprinciples. Experimental demonstration is also carried out. The results show that the opposite-sequence-titration mode,low surface-tension and viscosity medium help to maintain excellent compositional homogeneity and stoichiometry incoprecipitation product.