Objective To explore the association between social-emotional problems and the preliminary screening risk of autism spectrum disorders (ASD) in children aged 16-30 months, so as to provide reference for figuring out the high risk characteristics and early screening ASD. Methods A survey was conducted on 542 children who came to Fangshan Maternal and Children Health Hospital for routine health care from January 2018 to November 2019. Children's primary caregivers completed the Ages and Stages Questionnaire:social-emotional (ASQ-SE) for the children's age group under the guidance of trained doctors. On the same day or at adjacent times,primary caregivers were instructed to complete Modified Checklist for Autism in Toddlers-Revised with Follow Up (M-CHAT-R/F) under the guidance of doctors who were unaware of the ASQ-SE results. The correlation between ASQ-SE scores and M-CHAT-R scores was analyzed. Results Children with abnormal social emotion scored significantly higher on M-CHAT-R than children with normal social emotion (U_{18 months}=5 004. 00,U_24months=5 491. 50,U_{30 months}=409. 00,P＜0. 001). A higher proportion of children with abnormal social emotion were at risk of ASD as preliminary screened by M-CHAT-R (18 months:86. 96%,24 months:90%,30 months:80%). ASQ-SE scores were positively correlated with M-CHAT-R scores (r_{18 months}=0. 724,r_{24 months}=0. 693,r_{30 months}=0. 783,P＜0. 01). Conclusions Most of the children with social-emotional problems are at risk of ASD,and should be given more concern to,especially to younger children with social-emotional problems. Moreover,it is recommended that doctors should adopt the M-CHAT-R/F scale for ASD preliminary screening according to the actual situation.