Abstract: A method and apparatus for preparing methyl methacrylate (MMA) are provided. The method includes an aldol condensation reaction, a first distillation, a second distillation, a third distillation, a phase splitting, and a fourth distillation. Through the control of the process, the aldol condensation reaction can be performed when methyl propionate is used as the ninth material stream and formalin solution is used as the fifteenth stream material, MMA is obtained as the final product from the third material stream, and the waste with low content of residual formaldehyde is recovered from the eighth material stream.