Provided are a method and an apparatus for writing data into an SSD. The method includes: configuring, in the SSD, a low-level cell for storing open block data to form a low-level cell block; in response to receiving a data write instruction, writing data into a high-level cell of the SSD, the high-level cell has a unit capacity higher than that of the low-level cell; in response to that an existing time of a block that is not full of data in the high-level cell exceeds an open block status threshold value, determining the block that is not full of data as an open block and storing the open block in pending list; and in response to the existence of the open block in the pending list, transferring the open block to the low-level cell block through an internal memory, and closing the open block in the low-level cell block.