The present disclosure relates, according to some embodiments, to a data writing method in a storage system. The method comprises receiving data by the storage media controller, reading a non-volatile memory operation mode in the memory unit by a central control unit, in which the mode corresponds to a data reliability lower than the data reliability requirement of the storage system, reading a data reliability reduction condition in the memory unit by the central control unit, determining whether a system information related to the data meets the condition by the central control unit, and controlling the media control unit to write the data into the non-volatile memory according to the mode by the central control unit when the system information meets the condition.