The solvent evaporation method described in this study is simple and economic for microencapsulation.It requires no expensive and specialized equipment.The uniform, smooth, free-flowing and high antigenic recovery of Mycoplasma hyopneumoniae vaccine (MHV) microspheres are easily formed.The encapsulated MHV was effectively protected in simulated gastric juice and simulated intestinal conditions.From the practical point of view, the slow but continuous release of MHV from serum microspheres and the protective effect of serum against trypsin degradation can be used to formulate the oral vaccine for pigs.