Objective: To explore the association between parent-child connectedness and romantic relationships of secondary vocational school students and the moderating effect of peers romantic behavior, providing scientific basis for family and school health education. Methods: From March to April 2021，2 426 students from six secondary vocational and technical schools in Shanghai and Shaanxi Province were selected to conduct the survey by combining convenience sampling and cluster sampling.Electronic questionnaires were used to collect data on students family characteristics,oneself and peer romantic behaviors, and parent-child bonding. The t-test was employed for inter group comparisons, and binary Logistic regression analysis was conducted to examine the relationship between parent-child bonding levels, peer romantic behavior, and the romantic behavior of secondary vocational students. Results: The mother-child connection (2.63±0.77) was higher than that of father-child connection (2.48±0.78), with statistically significant difference ( t =6.83, P <0.01). Multivariable Logistic regression showed that overall father-child connectedness was negatively associated with students romantic relationships( OR =0.86，95% CI =0.76-0.97， P =0.02)and was only associated to girls romantic relationships when stratified by gender( OR =0.79，95% CI =0.66-0.93， P =0.01). Peers romantic relationships were positively associated with students romantic relationships ( OR =3.19-5.12, all P <0.01), and there was a moderating effect of the association between maternal connectedness and boys romantic relationships ( OR =1.67, 95% CI =1.05-2.66, P =0.03). Among boys without romantic peers, mother-child connectedness was negatively associated with their romantic relationships ( OR = 0.60 , 95% CI =0.36-0.99, P <0.05). In the total sample of Shanghai and girls of Shaanxi, father-child connectedness was negatively correlated with the romantic relationships of secondary vocational school students ( OR =0.84,0.65,95% CI =0.71-1.00,0.50-0.85,both P <0.05). Peer romantic relationships exhibited a negative moderating effect on the influence of mother-child connectedness on the romantic relationships of males in Shanghai ( OR =1.91, 95% CI =1.03-3.57, P <0.05). Conclusions The father-daughter connectedness is negatively correlated with girls romantic behavior, and peer romantic behavior weakens the correlation between mother-child connectedness and boys romantic behavior. Efforts should be made to enhance the parent-child connectedness of secondary vocational students and their ability to cope with peer influence, providing proper guidance for adolescents heterosexual interactions.