Core mineral spectrometer is one of the advanced and important tools for core digitalization, altered mineral mapping, ore deposits exploring, and ore-searching in surrounding mine and beneficiation process. In this letter, a new core mineral spectrometer (CMS 350) is designed and developed. The basic principle, structural design, function module, key components, data acquisition, and processing methods of CMS 350 are introduced. In addition, some applications and results of CMS 350 in Zijin Mining are presented to validate the performance of CMS 350.