A multi-hierarchy interconnect system for a cache system having a tag memory and a data memory includes an address interconnect scheduling device and a data interconnect scheduling device. The address interconnect scheduling device performs a tag bank arbitration to schedule address requests to a plurality of tag banks of the tag memory. The data interconnect scheduling device performs a data bank arbitration to schedule data requests to a plurality of data banks of the data memory. Besides, a multi-hierarchy interconnect method for a cache system having a tag memory and a data memory includes: performing a tag bank arbitration to schedule address requests to a plurality of tag banks of the tag memory, and performing a data bank arbitration to schedule data requests to a plurality of data banks of the data memory.