For the coordination of the supply chain under demand disturbances with a risk-averse manufacturer and a risk-averse retailer, conditional value-at-risk is used to evaluate the manufacturers and the retailers' degree of risk aversion and buy-back contract is introduced to establish supply chain coordination model under conventional and unconventional disruption.It is found that order quantity, promotion and contract decision have a certain degree of robustness under conventional disruption.If the demand disruption quantity is relatively large, conventional disruption leads to incoordination. While unconventional disruption surely leads to incoordination, by the adjustment of contract parameters, the supply chain can reach the coordination state again.