Highly purified 2,3-butanediol (2,3-BDO) was obtained from glycerol by using metabolically engineered Escherichia coli through biosynthetic pathways. The bio-elastomers with high strength and elasticity was then prepared from the synthetic 2,3-butanediol and several commercially renewable monomers as promising materials for engineering applications. The molecular weights, chemical structures, and thermal transitions of the bio-elastomers were confirmed by GPC, NMR, FTIR, TGA, DSC and WAXD. Importantly, the introduction of 2,3-BDO can limit and even prevent the crystallization of these bio-elastomers, which makes them amorphous and ensure their high elasticity. Furthermore, the bio-elastomers were highly reinforced with nanosilica which can meet the requirements for the majority of rubber products. Results of in vitro degradation tests prove these bio-elastomers can adjust the degradation rate of their composites by crosslinking. Cell adhesion and proliferation were adopted to evaluate the potential biocompatibility of SiO2/PBPSSI composites and the results indicated that all the SiO2/PBPSSI composites were essentially noncytotoxic. In general, the petroleum-independent monomers, relatively simple synthesis and adjustable degradation rate could greatly reduce environmental impact and the fine mechanical properties and excellent biocompatibility make these novel synthetic bio-elastomers sustainable materials for engineering applications.