Abstract: Based on the yield component data, yield data of spring highland barley and ten-day meteorological data in Xigazê, Xizang from 1992 to 2024, this study analyzed the variation characteristics of yield components of spring highland barley in Xigazê and the dominant influencing meteorological factors over the past 33 years by adopting climatic tendency rate, Pearson correlation coefficient, Mann-Kendall test, Cramer test and dominance analysis methods. The results showed that: (1) From 1992 to 2024, the spikelet number, grain number per spike and 1000-grain weight of spring highland barley in Xigazê presented significant increasing trends, with an average increase of 2.12 spikelets, 6.64 grains and 4.36 g per decade, respectively. The sterile spikelet rate decreased at a rate of −1.39%·(10a)^-1. (2) Ten-day mean temperature and mean minimum temperature exerted the greatest influence on spikelet number, sterile spikelet rate and grain number per spike. Precipitation in the first ten days of August was the dominant meteorological factor affecting 1000-grain weight, and all the above meteorological factors had positive effects on yield components. The unit yield of highland barley was mainly affected by spikelet number, with a contribution rate of 52.5%, followed by the sterile spikelet rate of 16.5%. (3) Abrupt changes of spikelet number, grain number per spike and 1000-grain weight occurred in 2011, 2013 and 2013, respectively. (4) Over the past 33 years, the dominant meteorological factors affecting highland barley yield components showed significant increasing trends, which facilitated the increase in spikelet number, grain number per spike and 1000-grain weight, as well as the reduction in sterile spikelet rate.