High strength and roughness are of importance for composite plastics used as mechanical structure parts. How to provide general and engineering plastics with high performances is one of the critical challenges in advanced manufacturing. In the past decade, the phase dispersion, interfacial interaction, injection molding simulation and fracture behaviors of composite plastics were investigated systematically in our research group in order to simultaneously reinforce and toughen polymer matrix. Here, we review the progress and advances which have been made in the above items.