Objective: To examine the association of joint effect of overweight and obesity with dyslipidemia on left ventricular hypertrophy (LVH) in children, so as to provide scientific evidence for the prevention of early cardiovascular damage in children. Methods: Data were obtained from the second followup crosssectional survey of Huantai Childhood Cardiovascular Health Cohort study in 2021, comprising 1 047 children aged 10-15 years with complete information. Based on overweight and obesity status and dyslipidemia status, all participants were divided into four groups:normal weight with normal lipid levels, normal weight with dyslipidemia, overweight and obesity with normal lipid levels, and overweight and obesity with dyslipidemia. Left ventricular mass index (LVMI) levels and prevalence of LVH across four groups were compared. Multivariate Logistic regression model was used to examine the association of joint effect of overweight and obesity with dyslipidemia on LVH in children. Results: There were significant differences in LVMI levels [(28.66±7.10, 29.63±4.71,31.49±5.86,32.65±4.80)g/m2.7] and prevalence of LVH (4.28%, 12.50%, 22.74%, 31.30%) across four groups (F/χ2=50.76, 90.92, P<0.05). After adjustment for confounding variables such as gender,age,screen time,sleep duration,fruit and vegetable intake,carbonated beverage consumption,physical activity and elevated blood pressure, compared to children with both normal weight and normal lipid levels, the risk of LVH in children with dyslipidemia alone increased (OR=3.27, 95%CI=1.57-6.82，P<0.05). Children with overweight and obesity alone also had a significantly increased risk of LVH (OR=6.33, 95%CI=3.76-10.66), and the highest risk was observed in those with both overweight and obesity with dyslipidemia (OR=9.66, 95%CI=5.35-17.43) (P<0.05). Conclusions The joint effect of overweight and obesity with dyslipidemia is positively correlated with LVH in children. To prevent LVH in children, both overweight and obesity with dyslipidemia should be paid attention to.