In order to improve the structure performance and reduce Life cycle cost of the structures, advanced fiber composite polymer is more and more frequently combined with conventional materials to develop new structures. FRP-concrete composite beams with prefabricated FRP shells, which are designed with steel bar as the main reinforcement and with suitable FRP participation proportion to improve the performance, are developed by us for their good integrated performance. The VIMP production process to produce the thin and large-scale FRP shell was developed and detailed in this paper and performance of the production was also examined. Results show that the FRP shell produced by VIMP are with rather good performance, and can be used in the composite beams. The VIMP is very suitable for this kind of thin and large-scale structures.