A class of processable and all-bio-based elastomers poly (epoxidized soybean oil-co-decamethylene diamine, PESD) were synthesized only from epoxidized soybean oil (ESO) and decamethylene diamine (DDA). The glycerol centre of ESO was broken on purpose by ammonolysis with diamine to destroy the original crosslink structure, which was confirmed by FTIR and 1H NMR. Different molar ratios of ESO to DDA were used to form various PESDs, and the effect of the molar ratio on the structure and properties of these PESDs was investigated. PESD-3(molar ratio of DDA to ESO is 2:1) was found to have the highest molecular weight and was most suitable for further processing. Then PESD-3 was selected for crosslinking by using succinic anhydride as cross-linker. The effects of the succinic anhydride content on properties were studied. The tensile strength of the cross-linked bioelastomer could be flexibly adjusted from 1 to 8.5 MPa without any reinforcing filler. We also found that the bioelastomer possessed good damping property.