Background To master the distribution and changing characteristics of dental diseases is of great significance for the dental emergency center in order to strengthen the treatment abilities of medical staff and the effective use of emergency resources in the face of public health emergencies of highly infectious respiratory diseases. Methods The medical records of 4158 cases of dental emergency patients from 2019 to 2020 were retrospectively analyzed,with patients being divided into the pre-SARS-COV-2 group and the during SARS-COV-2 group according to the date of their admittance to the dental emergency center.The dental emergency patients demographicsn data,day and time,diagnoses,treatment approaches were compared before and during the SARS-COV-2. Results During the SARS-COV-2,the number of dental emergency visits increased by 29.7% compared with those before the SARS-COV-2.The peak of the number of patients at weekends and at night is not obvious compared with the pre-SARS-COV-2 group.Duing the SARS-COV-2 Male(n=286,58.1%) were more likely than female(n=206,41.9%) to visit the dental emergency center for trauma P<0.05,female(n=242,60.8%) were more likely than male(n=156,39.2%) to visit the dental emergency center for Acute gingivitis and Acute pericoronitis P<0.05.A major diagnoses change is Acute Pulpitis (K04.0) and Acute apical periodontitis (K04.4) increased by 9.2%,Acute gingivitis (K05.0) and Acute pericoronitis(K05.2) increased by 3.5%,Open wound of lip and oral cavity (S01.5)fell 17.9%,others (non-emergency diseases) increased by 6.8%,compare with the pre-SARS-COV-2.Among the treatment methods,during the pre-SARS-COV-2,304(17.7%)received a prescription for Antibiotics and Analgesics,1485(86.5%) received a prescription for local treatment.During the SARS-COV-2,958(39.2%)received a prescription for Antibiotics and Analgesics,1636(67.0%) received a prescription for local treatment. Conclusion SARS-COV-2 led to changes in the characteristics of dental emergency patients.Trauma,Acute Pulpitis,Acute periodontitis Acute periodontitis are the leading reason why patients go to the dental emergency.The dental emergency center should optimize the treatment procedures,optimize the staffing and reasonably allocate materials according to the changes,to improve the on-site treatment capacity and provide adequate dental emergency care. .