In conventional geophysical exploration method for pegmatite lithium mineral exploration, there exist the problems that the difference between the orebody and the surrounding rock is not significant, the application effect is poor, and the geochemical exploration method has no obvious effect on the concealed lithium deposit. In view of such a situation, the authors investigated the technical problems related to the application of geogas method in the exploration of pegmatite lithium deposits. With Kalu'an in Xinjiang as the study area, the authors deployed two geogas research sections with a total length of 6 605 m, and completed the case study of pegmatite lithium deposits with 191 measuring points, which was performed for the first time both in China and abroad. The values of 39 elements such as Li, Rb, Be, Cs, Nb, and Y were determined. On such a basis, the characteristics of geogas anomalies in the Kaluan pegmatite lithium deposit were studied. The results show that significant gas anomalies containing Li, Rb, Be, Cs, Nb, Y, and other elements can be captured on the tilted side of the pegmatite lithium veins, that, above the barren pegmatite, the abnormal amplitude of geogas in Rb element will increase, and the anomaly amplitude of other elements will obviously decrease, with no gas anomaly, and that, in other lithologies, there is no abnormal geogas. It is confirmed that the geogas method is accurate and effective in the search for pegmatite lithium deposits.