Objective: To understand and analyze the epidemiological characteristics of dental caries in children and its effects on jaw function, so as to prevent occurrence of abnormality of jaw function. Methods: In October 2020, 860 cases of children from 5 kindergartens and 3 primary schools in Beijing were selected by adopting the convenience sampling method. All of them received oral examination, and the questionnaire according to the fourth national oral health epidemiological survey standard, including demographic information, eating habits, oral hygiene habits, oral health care,etc. The epidemiological characteristics of dental caries in children and its effects on jaw function were analyzed. Results: A total of 190 children had dental caries, with a dental caries incidence rate of 22.09%. Dental caries in children s deciduous teeth or permanent teeth was related to age, residence, parents education level,whethe to eat before going to bed, whether eating sweet food, tooth brushing age, daily brushing frequency, whether parents have assisted tooth brushing, whether regular oral examination, whether parents have received oral health guidance( χ 2= 5.04 ,4.70，75.37，7.91，12.03，9.30，7.64，255.47，253.27，11.38, P <0.05). Compared with the noncaries group[(81.52±3.16， 80.54± 1.52，1.92±0.25，31.52±1.62，33.63±3.41，50.72±1.68)°], the sella nasion A point(SNA), sella nasion B point(SNB),A point nasion B point(ANB),frankfot horizontal mandibular plane angle(FH MP),skull nasion mandibular plane angle(SN MP),anteriors relationship palataplane mandibular(Ptm ANS) decreased in the dental caries group[(78.62±2.11，79.35±1.02，1.68±0.32，30.69±0.45，32.15±3.02，48.62±1.21)°](t=78.62,79.35,10.94, 30.69, 32.15, 48.62, P<0.05). Conclusion The prevalence of caries in children was high and jaw structure abnormalities and dysfunction. It is suggested that caries prevention and control work should be carried out early to strengthen the prevention and control of oral disease education work.