Objective To investigate the prevalence of soil-transmitted nematode infections in national surveillance sites of Guizhou Province from 2020 to 2023, so as to provide insights into formulation of the control strategy in the province. Methods National soil-transmitted nematodiasis surveillance sites were assigned in 9 cities (prefectures) of Guizhou Province from 2020 to 2023, including 6 fixed surveillance sites and 7 to 11 mobile surveillance sites each year. At each surveillance site, with the county as the unit, one administrative village was randomly selected from each of the five regions (eastern, western, southern, northern, and central) within the county to conduct monitoring. At least 200 permanent residents at ages of 3 years and older were randomly sampled from each administrative village, and at least 1 000 residents were randomly sampled from each surveillance site. Participants’ fecal samples were collected for identification of nematode eggs with the modified Kato-Katz thick smear method (two slides for each stool sample), and the time-, region- and population-specific prevalence rates of soil-transmitted nematode human infections were compared. Differences of proportions were tested for statistical significance with chi-square test. Results A total of 60 573 residents received surveillance on soil-transmitted nematode infections in Guizhou Province from 2020 to 2023, and the average prevalence of soil-transmitted nematode infections was 1.07% (651/60 573). The prevalence of soil-transmitted nematode infections was 1.81% (255/14 075), 1.32% (226/17 138), 0.75% (98/13 100), and 0.44% (72/16 260) from 2020 to 2023, respectively, which appeared a tendency towards a decline over years, and there was a significant difference among years (χ² = 155.7, P < 0.01). The average prevalence rates of Ascaris lumbricoides, hookworm, Trichuris trichiura infections were 0.43% (260/60 573), 0.37% (225/60 573) and 0.35% (213/60 573), respectively. The prevalence of both A. lumbricoides (0.89%, 0.50%, 0.24%, 0.11%) and T. trichiura infection (0.72%, 0.48%, 0.19%, 0.02%) appeared a tendency towards a decline over years from 2020 to 2023, and there were significant differences among years （χ² = 120.2, 123.1, both P < 0.01). The highest prevalence of soil-transmitted nematode infections was detected in Qiandongnan Prefecture (2.49%, 254/10 199), and the lowest in Guiyang City (0.10%, 7/7 036), showing a region-specific prevalence rate of infections (χ² = 416.4, P < 0.01). The prevalence of soil-transmitted nematode infections was 0.89% (262/29 396) and (1.25%, 389/31 177) among men and women, respectively. The highest prevalence was seen among residents at ages of 70 years and older 1.56% (106/6 808), followed by at ages of 3 to 9 years (1.46%, 132/9 012). The highest prevalence of soil-transmitted nematode infections was detected among Miao minority ethnic residents (2.09%, 160/7 639). The highest prevalence of soil-transmitted nematode infections was detected among students (1.44%, 188/13 019). In addition, the highest prevalence of soil-transmitted nematode infections was detected among illiterate residents (2.04%, 109/5 332). There were statistically significant differences among populations with different genders, age groups, ethnicities, occupations, and educational levels (χ² = 18.1, 92.7, 151.1, 56.6, 146.5，all P < 0.01). Conclusion The prevalence of soil-transmitted nematode infections appeared a tendency towards a decline in Guizhou Province over years from 2020 to 2023. However, higher attention should still be paid to key populations, including women, children, the elderly, ethnic minority residents, farmers (herdsmen), and individuals with low educational levels to facilitate the transmission control and interruption of soil-transmitted nematodiasis in Guizhou Province.