A data reconstruction method is performed in a distributed storage system. A primary storage node in the distributed storage system performs EC encoding on to-be-written data to generate an EC stripe, and stores, on each storage node, each EC block in the EC stripe. When a fault occurs on some storage nodes and causes a write failure of EC blocks, the primary storage node locally stores an EC block allocated to a storage node to which the write fails and generates metadata information required for data reconstruction. After the storage node recovers from the fault, the primary storage node sends, to the storage node, the stored EC block allocated to the storage node to which the write fails and the metadata information corresponding to the EC block, so that the storage node that recovers from the fault completes the data reconstruction.