The embodiment of the invention relates to a method and a system for processing data in a storage system. The method comprises the steps of: according to an identifier of object data, determining an initial pt group by a Hash algorithm; determining the use heat and a reference value of m object storage devices (OSDs) in the initial pt group, wherein the reference value is the minimum value of the use heat of k OSDs corresponding to at least one pt group in n pt groups; when the difference value of the use heat of m OSDs in the initial pt group and the reference value is more than or equal to the OSD with a preset threshold value, determining the pt group, with the minimal comprehensive weighted value, in the n pt groups as the target pt group, otherwise, determining the initial pt group as the target pt group; storing the object data into the m OSDs corresponding to the target pt group. The method and the system for processing the data in the storage system, provided by the embodiment of the invention, can dynamically adjust an object data written disk and guarantee uniform distribution of disk data.