Multimorbidity of common diseases in children and adolescents refers to the coexistence of two or more common diseases or chronic health problems in the same individual. In recent years, the multimorbidity of common diseases in children and adolescents has become increasingly serious, which has enormously increased disease burden and socio-economic losses. These diseases typically share similar influencing factors, such as adverse environmental factors, unhealthy diets, lack of outdoor activities and physical exercise, sedentary lifestyle, excessive use of electronic devices, and disturbed sleep rhythms. Multidimensional interventions targeting these factors are effective methods of preventing and controlling multimorbidity of common diseases in children and adolescents. This review summarizes the public health burden, epidemiological data, risk factors, and behavioral interventions for multimorbidity of common diseases in children and adolescents to strengthen relevant research, develop effective intervention strategies, reduce the disease burden of children and adolescents, and promote their healthy growth.