A data storage method includes the following steps: storing data to be stored into a mutable table, the mutable table being located in a RAM. If a storage content of the mutable table is greater than or equal to a preset storage content threshold, modifying the mutable table into an immutable table and stopping receiving storage of the data to be stored; if a storage content of a lowest level in a disk is greater than or equal to a storage content threshold of a present level, and next level higher in the disk is stored with columnar format, storing data of the lowest level to the next level in the columnar format; and if the lowest level is stored with row format, storing data in the immutable table to the lowest level in the row format.