This study investigated the impact of family financial status on Chinese children's health-related traits and their behavior in controlling COVID-19. When the children were 7 years old, their guardians provided information on family financial status. When the children reached 10 years old, they completed questionnaires concerning their own health consciousness and health status. At age 11, during the COVID-19 pandemic in 2020, they filled out questionnaires on perceived vulnerability to disease and disease control behavior. The findings revealed that higher health consciousness is associated with better health, particularly among children from financially challenged families. Additionally, a greater perception of vulnerability to disease is linked to increased COVID-19 control behaviors, particularly in children with high health consciousness in affluent families. These results contribute to our understanding of how children's personal health-related traits and family financial status interact to shape their response to the COVID-19 pandemic.