During the COVID-19 pandemic, delirium became a major complication that worsened patient outcomes. However, the factors influencing the severity of delirium in patients with COVID-19 have not been determined. We conducted this study to detect influencing factors associated with subtypes of delirium in patients with COVID-19. We included 1774 adult inpatients with COVID-19 from January to February 2023 at 7 sites in China. And used the 3 min Confusion Assessment Method and the Richmond Agitation-Sedation Scale for site assessment to identify and classify subtypes of delirium. Laboratory data were obtained from the Hospital Information System. After multivariate analysis, hypoactive delirium was significantly associated with age, the serum albumin concentration, frailty and sarcopenia, and health and nutritional status. Mixed delirium was significantly associated with age, D-dimer level, sarcopenia, health status and nutritional status. Additionally, hyperactive delirium was significantly associated with age, procalcitonin levels, frailty status and health status. Our findings suggest that poor nutritional status and low serum albumin concentration can help detect patients at high risk of developing hypoactive and mixed delirium. Additionally, clinical staff should pay more attention to patients with inflammatory conditions to assess and detect delirium because many influencing factors are involved in the common pathological mechanism of inflammation.