Objective: To analyze the predictive value of serum albumin (ALB) level for the prognosis of children with autoimmune encephalitis (AE). Methods: Seventy-eight children with AE were divided into the study group (36 cases, with serum ALB level <40 g/L) and the control group (42 cases, with serum ALB level ≥40 g/L) according to the level of serum ALB in admission. The general data, the auxiliary examination indexes, and the clinical symptoms between the patients in the two groups were compared and analyzed, and the short-term prognosis after 3 months of immunotherapy as followed up. Results: In the study group and the control group, there were 2 and 3 children lost their visits, so 34 and 39 children were included into the two groups, respectively. There was no significant difference in general data information between the two groups (P>0.05). The proportion of modified Rankin scale (mRS) score ≥4 of the children in the study group was higher than that in the control group, and the antibody type was mainly anti N-methyl-D-aspartic acid receptor (NMDAR) antibody, the clinical classification is mainly anti-NMDAR encephalitis, the differences were statistically significant (P<0.05), while the differences of other auxiliary examination indexes between the two groups were not statistically significant (P>0.05). The proportion of children with consciousness disorder in the study group was higher than that in the control group, the difference was statistically significant (P<0.05), while the proportions of children with other symptoms were not statistically significant (P>0.05). At the end of the follow-up period, 48 children had a good prognosis, 25 children had a bad prognosis. The proportion of ALB reduction, the proportion of mRs score ≥4, the abnormal magnetic resonance imaging (MRI) ratio, the proportion of abnormal electroencephalogram (EEG) in the children with poor prognosis were higher than those in the patients with good prognosis, the differences were statistically significant (P<0.05). Logistic multiple regression analysis showed that the poor prognosis of AE children was correlated with decreased ALB and mRs score ≥4 (P<0.05). Receiver operating characteristic (ROC) curve analysis showed that area under the curve of ROC (AUC ROC) of ALB reduction and mRs score ≥4 to predict the poor prognosis of AE children were 0.785 and 0.684 respectively (P<0.05), among which, AUC ROC of ALB reduction was higher, the sensitivity and specificity were 0.84 and 0.729 respectively. Conclusion: AE children with lower serum ALB level before immunotherapy show more serious clinical symptoms, more consciousness disorder, and more common anti NMDAR antibody. The decrease of serum ALB level is related to the poor short-term prognosis of children, which can be used as an auxiliary index to predict the short-term prognosis of children with AE.