This study aims to identify multimorbidity patterns and examine whether health poverty vulnerability (HPV) varies among adults aged 45 years or more. Data from 4338 participants were extracted from a Chinese cross-sectional study. Latent class analysis was used to identify multimorbidity patterns based on 11 self-reported chronic diseases. A 3-stage feasible generalized least-squares method was used to measure the HPV. The associations and influencing factors were analyzed using the Tobit model. The mean HPV values were 0.105 ± 0.225 and 0.329 ± 0.357, based on extreme poverty and those of low- and middle-income countries’ poverty line, respectively. Four latent multimorbidity patterns were identified, comprising hypertension (57.33%), cardiovascular diseases (19.94%), the musculoskeletal system (13.09%), and spine (9.64%). The HPV value from hypertension (coefficient [Coef] =0.03, 95% confidence interval (CI) = 0.00–0.05) was significantly higher than that of the musculoskeletal system based on extreme poverty. In addition, the HPV values for hypertension (Coef =0.08, 95% CI = 0.05–0.11), spine (Coef =0.06, 95% CI = 0.02–0.11), and cardiovascular diseases (Coef =0.07, 95% CI = 0.03–0.11) were significantly high based on low- and middle-income countries’ poverty line. Age ≥75 years, registered poor households, catastrophic medical expenditure, and toilet style were major risk factors. Although the multimorbidity pattern-induced HPV has been significant improved on extreme poverty, it still poses a very serious challenge with regard to low- to middle-income countries’ poverty line. The sensitivity analysis proved the robustness of the results. Policymakers should focus on adults with 3 multimorbidity patterns, namely, registered poor households, age ≥75 years, and catastrophic health expenditure, to adopt targeted interventions to prevent and eliminate HPV.