Embodiments of the present invention provide a data storage method and system. The data storage method is applied to a data storage system, the data storage system includes a packet processing device, a processor, an off-chip memory, and a first counter corresponding to the off-chip memory, the off-chip memory is configured to store a count value of the first counter corresponding to the off-chip memory, and the packet processing device is configured to receive and process a service packet, count the service packet by using the first counter, and maintain an original address at which the count value of the first counter is stored in the off-chip memory. The method includes: scrambling, by the processor, the original address to obtain a scrambled address; and storing, by the processor, the count value of the first counter in a storage space corresponding to the scrambled address in the off-chip memory.