Hypertension and triglyceride-glucose (TyG) index are both closely associated with insulin resistance, respectively, while the role of TyG index and the association between TyG index and obesity on hypertension risk remain unclear. This study aimed to examine the association and interactive effect of TyG index and obesity on hypertension risk. There was a population-based cross-sectional survey in Henan, China. Multivariate logistic regression analysis was performed to estimate the association between TyG index and the risk of prehypertension and hypertension. The area under curves (AUC) of TyG index and joint indicators (TyG index and obesity indices) was calculated to assess the predictive ability of hypertension. The additive interaction was computed to evaluate the interactive effect between TyG index and obesity. Compared with the lowest TyG quartile, participants in the highest quartile had an increased risk of prehypertension (odds ratio (OR): 1.69, 95% confidence interval (CI): 1.18-2.44) and hypertension (OR: 2.53, 95% CI: 1.80-3.57). The AUCs of joint indicators were significantly higher than TyG index in predicting hypertension (all P < 0.01). Presence of higher TyG index enhanced the ORs of waist-to-height ratio (WHtR) and percent body fat (PBF) from 3.50 (95% CI: 2.55-4.80) to 6.51 (95% CI: 4.81-8.82), and from 3.88 (95% CI: 2.78-5.42) to 7.09 (95% CI: 5.11-9.84) with significant additive interaction on hypertension, respectively. Increased TyG index was significantly associated with a higher risk of prehypertension and hypertension in Chinese adults. Besides, our results also demonstrated the interactions of TyG index and WHtR and PBF on hypertension risk.