A low temperature cure resin has been prepared successfully by applying self designed/synthesized cure agent and commercial epoxies through slurry mixing process. Low temperature/vacuum bag cure prepreg with excellent drapeability & spreadability and over 10 days storage life at room temperature could be prepared by hot/melt technique. The cure and post cure parameters of manufacturing composites were optimized. The main properties of low temperature/vacuum bag cure composite have been determined. Results indicated that the low temperature/vacuum bag cure composite system had excellent mechanical properties and its long service temperature could reach 80°C. The influence of ultrasonic irradiation applied during the manufacturing process on the properties of the composite was discussed, and results showed that the ultrasonic irradiation improved the properties of composite greatly and suggested a novel strategy to improve the mechanical properties of low temperature cure composite systems.