Dental general anesthesia (DGA) is a safe and high-quality restorative and preventive treatment option for children with severe early childhood caries (S-ECC), who require extensive dental treatment and exhibit anxiety and emotional or cognitive immaturity or are medically compromised. However, several postoperative complications have been reported in children under DGA. This study aimed to evaluate and analyze the prevalence of the relevant factors of postoperative complications in healthy Chinese children following DGA to provide a foundation for pre-, intra-, and postoperative overall health management for healthy and disabled children after DGA. A total of 369 systematically healthy Chinese children (36–71 months old) undergoing a DGA were studied. Data were collected on patients’ histories, characteristics, anesthesia, and dental procedures. Parents or caregivers were interviewed before and 72 hours after the procedure. Data were analyzed using logistic regression. Approximately 94.86% of the enrolled children reported one or more complications. The most prevalent complication was postoperative pain (62.70%), followed by weariness, agitation, masticatory problems, drowsiness, oral bleeding, coughing, fever, sore throat, nausea, constipation, epistaxis, vomiting, excitement, and diarrhea. The long duration of the operation was a risk factor for postoperative pain and weariness. A high nutritional status could be a protective factor for postoperative fever. Prolonged operation means complex treatment, such as pulp therapy or extraction. We speculate that the longer the duration is, the more difficult the dental procedures are. The accumulation of discomfort leads to pain. We suspect that children in lower nutritional levels are more likely to suffer from bacteremia or dehydration, resulting in fever. Postoperative pain was the most prevalent complication after the DGA. A decrease in dental procedure duration might reduce the odds of postoperative pain and weariness. A high nutritional status could be a protective factor for postoperative fever. Children with low nutritional status could be more susceptible to postoperative fever.