Abstract: Based on the ground and high-altitude observation data, NCEP1°×1°reanalysis data, a case of Yunnan-Guizhou quasi-stationary front (YGQF) on January 9—22, 2020 was selected. The characteristics of YGQF, the frontogenesis mechanism and its influence on precipitation in Guizhou were analyzed with statistical and synoptic diagnostic methods. The results showed that: (1) During the impact period of YGQF, the front moved eastward or westward, and the intensity of the front changed continuously. When the front was located to the west of 103°E, the front moved westward and its intensity weakened. When the front was located to the east of 104°E, the front moved westward and its intensity increased, otherwise it weakened. When the front was located between 103°E and 104°E, its intensity was strong. (2) The movement and intensity characteristics of YGQF were influenced by surface temperature and pressure, low-level wind, and precipitation of the front. When the pressure increased, the temperature decreased in the cold zone, and the pressure increased in the warm zone, the front moved westward, otherwise it moved eastward. When the front was located to the west of 104°E, the southwest wind at 700 hPa strengthened and the front moved eastward. When the precipitation of YGQF increased, the front moved westward, with weak or no precipitation, and the front moved eastward or remained stationary. (3) The non-adiabatic heating term (F1) in the frontogenesis function had a significant impact on the diurnal variation of YGQF. F1 caused the front to move eastward and weaken during the day, while F1 caused the front to move westward and strengthen at night. The sum of horizontal divergence term (F2) and horizontal deformation term (F3) mainly played a frontogenetic role under the influence of cold air, and was the main driving factor for the formation of YGQF. (4) The correlation was weak between the movement, intensity of YGQF and the precipitation in Guizhou. The precipitation in Guizhou corresponded well with the trough at 500 hPa and the southwest warm-humid airflow at 700 hPa during the maintenance period of YGQF. Under its influence, the precipitation range expanded and the intensity strengthened.