The invention relates to a safety cloud storage method for use in a multi-cloud environment and solves the safety storage problem of cloud data. The method includes data storage and data reading; data storage includes the steps of 1, data partitioning, 2, data deduplication, 3, data encoding, 4, data encrypting, 5, trans-cloud transmission management; data reading includes the steps of 1, metadata reading, 2, reading optimizing, 3, data reading, 4, data decrypting, 5, data decoding and 6, data assembling.