This paper is the result of mineral exploration engineering. In recent years, with the large-scale exploitation of mica-type lithium deposits in the Northwest of Jiangxi Province, hard-rock-type lithium deposits, such as greisen-type and altered granite-type in south China block, have gradually attracted more and more attention. Southern Jiangxi Province is a world-famous quartz vein-type wolframite mining district and producing base. In the past, exploration and research work mainly focused on the tungsten and tin deposits. [Objective]In order to further understand whether lithium mineralization exists in quartz vein type tungsten tin ore and its geological characteristics. [Methods]This study was conducted through systematic microscope identification and laser ablation inductively coupled plasma mass spectrometer (LA-ICP-MS) analysis. [Results]Greisen-type lithium ore was found in the deep part of Shilei tungsten and tin deposit in Chongyuyou Ore cluster located in the Southern Jiangxi Province. The lithium ore body occurred at the top of the deep concealed granite body, and distributed on two sides of W-Sn-bearing quartz-vein and feldspar quartz-vein. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analysis and microscope identification show that lithium mainly found in muscovite-phengite. The average Li₂O content of greisen in hornfelsic sandstone is 0.25%, the average Li₂O content of quartz (feldspar) vein greisen in mica granite is 0.21%, and the average Li₂O content of mica vein-bearing greisen developed in mica granite is 0.22%, which shows potential comprehensive utilization value. [Conclusions]In this study, lithium mineralization of industrial significance is identified in Shilei quartz vein-type tungsten tin deposit. The discovery enriched the metallogenic theory of tungsten and tin deposits in the Southern Jiangxi Province, broadened the prospecting and exploration ideas of greisen-type lithium deposits in Chongyuyou ore cluster, and provided a basis for further expanding the prospecting space of hard-rock-type lithium deposit in South China Block.