Background: Overweight/obesity is associated with pregnancy-related disorders, such as gestational diabetes mellitus (GDM) and excessive gestational weight gain (GWG). Although multiple interventions have been proposed to prevent GDM and restrict GWG, our knowledge of their comparative efficacy is limited. Objective: To evaluate the effectiveness and identify the optimal intervention strategy to prevent GDM and restrict GWG among overweight/obese pregnant women. Methods: Randomized controlled trials that recruited overweight/obese pregnant women at <20 gestational week were obtained. Predictive and confidence interval plot and surface under the cumulative ranking (SUCRA) were performed using Stata statistical software to determine and compare the efficacy of interventions (diet, physical activity (PA), diet + PA intervention and medication). Results: 23 studies with a total of 8877 participants were eligible for analysis. Our results indicated that although neither PA, diet + PA, diet nor medication intervention could significantly protect overweight/obese women from the development of GDM, there was a trend that PA and diet + PA intervention were preventive factors of GDM. Of these, PA intervention (SUCRA, 82.8%) ranked as the superior strategy, and diet intervention (SUCRA, 19.7%) was the least efficacious regimen. Furthermore, interventions of diet, PA and diet + PA were significantly beneficial for GWG restriction, whereas medication intervention could not restrict GWG. In detail, diet intervention (SUCRA, 19.7%) ranked as the optimal regimen, whilst PA intervention (SUCRA, 62.3%) ranked as the least efficacious regimen. Conclusion: Although none of the interventions could offer remarkable benefit for GDM prevention, interventions of diet, PA and diet + PA were significant factors to restrict GWG. In aggregate, diet + PA intervention seemed the superior choice for the prevention of both GDM and excessive GWG. Registration: PROSPERO CRD42022313542.