The invention relates to a smart card system which comprises a central processing unit (CPU), a hardware algorithm module used for algorithm calculation, a memorizer used for storing program and data, a random access memory (RAM) and a firewall module, wherein the RAM module is used for providing algorithm running space as ordinary RAM used for a central processor unit (CPU) for a smart card hardware algorithm module. The firewall module is used for providing safeguard for a smart card algorithm RAM module. Due to the smart card system, in the process of algorithm running, only the hardware algorithm module accounts for the RAM. On the one hand, efficiency of the algorithm running is greatly improved, on the other hand, only the hardware algorithm module can read middle results of the algorithm running, and therefore the hacktivism that an illegal program uses CPU to maliciously read the results of the algorithm running to speculate a secret key or algorithm implementation is eliminated, and absolutely reliability of the hardware algorithm module is ensured.