Abstract: As the classical simulation based soft error reliability evaluation approaches are incomplete and the existing formal technique based approaches require experience and support from experts, a fault propagation feature and equivalence checking guided soft error reliability evaluation approach is proposed in this work.Fault propagation sequential dependence graph (SDG) is advanced to extract the fault propagation behavior feature of soft errors.And based on the SDG, the equivalence between the original circuit and the faulty circuit is checked to identify the sequential units which are vulnerable to soft errors.Experimental results show that the propose approach can not only can locate all the soft error vulnerable spots, but also check the effectiveness of the fault tolerance logics in circuits.