A DDR5 SDRAM DIMM slot detection system and a method thereof are disclosed. A first detection board is serially connected to a second detection board, a JTAG controller converts a DIMM detection instruction, which is generated by a detection device, into a DIMM detection instruction in JTAG format; the DIMM detection instruction in JTAG format is provided to the first detection board or second detection board through the adapter circuit board, so as to detect DDR5 SDRAM DIMM slots of the circuit board under test, thereby achieving the technical effect of improving efficiency in detection for DDR5 SDRAM DIMM connection interface.