The purpose of the study was to determine if there was a relationship between night sleep duration and hypertension, and to evaluate as to whether blood lipid levels played a role in this relationship. A total of 37,317 participants aged 18–79 years were included in this study. Night sleep duration was classified as <5, 5-, 6-, 7-, 8-, 9-, and ≥10 hours. Logistic regression and restricted cubic spline analysis was carried out to evaluate the association of sleep duration with hypertension. Compared with reference sleep duration (7 hours), in males, the multivariate odds ratios (ORs) (95% confidence interval [95% CI]) of the groups with longest sleep duration (≥10 hours) and shortest sleep duration (<5 hours) for hypertension was 1.52 (1.25–1.84) and 1.07 (0.80–1.44), respectively. Similarly, the longest sleep duration was associated with diagnosed hypertension (1.21, 1.00–1.45) in females. The OR for an indirect effect of sleep duration through low-density lipoprotein cholesterol (LDL-C) on hypertension was 1.085 (95% CI 1.038–1.137). Overall, a 3.5% possibility of hypertension being associated with sleep duration was attributable to LDL-C. In summary, a relationship between sleep duration and hypertension was observed in this rural population. LDL-C appeared to partially mediate the effect of sleep duration on hypertension in males.