This paper describes the hardware and software of the probe, the core component of the new generation Xray fluorescence logging instrument. SiPIN semiconductor detector has been adopted in XRF logging probe and a structure fixing the excitation source on both sides of the detector has been designed. In this system, the ARM7 microprocessor is used as a control core, and RS485 is employed as communication protocol, with the maximum measurable depth being 2 000 meters below the ground. This system was tentatively applied in the Lala copper mine of Huili County, Sichuan Province, and the results show that the Xray fluorescence logging instrument can obtain the content of elements in various ores within rocks and sidewalls rapidly. Hence this system provides an effective analytical method for exploring deeper resources.