Green composite made from ramie fabric and polypropylene (PP) is a kind of recyclable and environmental friendly material. Ramie fiber tows have relatively good mechanical properties comparing with other bast fibers, and hence the fabric woven by ramie yarn shows excellent in-plane mechanical behaviors. PP can be fully recovered and recycling used for its thermoplastic character. Ramie fabrics reinforced by PP have better shape formability and maintenance. In this paper, we proposed a plain weave in sample dobby loom, and reinforced four laid-layers together by PP particle through hot pressing. The mechanical behaviors of the ramie-PP composite were tested by MTS-810 Material Testing System in weft and warp directions separately which were essential parameters to the following topology optimization in finite element analysis (FEA) software. A body of eco-power automobile consisting of shell and chassis was original designed in Pro/E® Wildfire 5.0. For the chassis is the main bearing structure, it is an important part in the eco-power automobile body and was chosen to be topology optimized. Fiber volume fraction and structure optimization of the chassis model are evaluated and simulated to guide the material formation of manufacture progress.