Abstract: Avicel-acrylate composite microsphere was prepared using inverse-phase suspension polymerization under following conditions:oil phase/water phase (O/W,mass ratio)2.4:1,mass ratio of alkylphenol ethoxylate (OP) and sodium lauryl sulfate (SLS) 4:1,mass ratio of methyl methacrylate (MMA), butyl acrylate (BA) and N-hydroxymethyl acrylamide (NMA) 35:15:3, and stirring speed 200-400r/min. Results of analysis on interior structure and properties of microsphere, crystallinity of avicel before and after reaction indicated that avicel participated crosslinking reaction and was encapsulated by polyacrylate. High flexural performance of translucent yellow molding plastics with low water absorption was obtained by blending composite microspheres of 85nm diameter with polymethyl methacrylate (PMMA).