The treatment of suicidal ideation in patients with depression has been a major problem faced by psychiatric and emergency departments, and reasonable drug selection is particularly important. Ketamine has been shown to reduce suicidal ideation rapidly, but the strength of the effect is unclear and there is little evidence-based medical evidence to support this. We systematically searched all articles published on PubMed, Cochrane Library, Web of Science, CNKI and EMBASE. Stata 15 and R 4.1.3 were used for meta-analysis, and odds ratios were calculated in fixed effects or random effects models based on the heterogeneity test results. Our search resulted in 505 articles; we analyzed 14 studies, which included 1,380 participants. The 14 studies included 10 randomized controlled trial (RCT) studies and 4 single-arm studies. Our study suggests that, ketamine has a significant therapeutic effect on suicidal ideation throughout the treatment cycle. We performed network meta-analyses(NMA) and pairwise meta-analyses to compare the efficacy of ketamine in the reduction of suicidal ideation. There was a significant reduction in suicidal ideation within the first day after treatment (NMA ketamine day1 RR = 10.02, 95%CI = 4.24 to 23.68). In repeated treatment, the degree of recovery of suicidal ideation after the last dose was significantly greater than that after the first dose (RR = 0.56, 95%CI = 0.51 to 0.62). Recovery of suicidal ideation was also significantly better in the treatment end point than in the placebo group at the same time point (NMA ketamine day26 RR = 4.29, 95%CI = 1.41 to 13.08). This is the first network meta-analysis to demonstrate the role of ketamine in the alleviation of suicidal ideation. Our network meta-analysis also compared the effects of different drugs at different time points, which was not done in previous studies. This is of great reference significance for future drug research andrational drug use.