Power failure safeguard method and device for nonvolatile memory

The invention discloses a power failure safeguard method and device for a nonvolatile memory. The method comprises the steps that metadata is backed up to a first nonvolatile memory medium before a power failure; the metadata backed up in the first nonvolatile memory medium is acquired after power is recovered; and data in a source storage device is recovered according to the metadata, wherein the metadata contains first storage position information of the data in the source storage device and second storage position information of data corresponding to the data in the source storage device. The technical scheme in the embodiment guarantees that the metadata is backed up to the first nonvolatile memory medium in real time, so that the security of the metadata is guaranteed; when a system has an abnormal power failure, the metadata backed up in the first nonvolatile memory medium is acquired after power is recovered, then data in a second nonvolatile memory medium is recovered into the source storage device ac