Purpose: This study aimed to construct and test a hypothetical model to explain predictive factors affecting nursing students' satisfaction and self-confidence in simulation-based education based on the National League for Nursing Jeffries Simulation Theory. Methods: A cross-sectional study was conducted on 305 fourth-year nursing students with experience in simulation-based education enrolled at universities in Gangwon-do, Gyeongsangbuk-do, and Gyeonggi-do. Data were analyzed using SPSS 25.0 and AMOS 25.0. Results: The hypothetical model showed good fit with the empirical data: χ2/df 2.17, RMSEA=.01, RMR=.01, GFI=.95, AGFI=.91, NFI=.94, TLI=.95, CFI=.97, and PNFI=.68. Simulation design characteristics, teaching efficiency, and flow were found to affect satisfaction and self-confidence directly. A bootstrap test indicated that teaching efficiency and flow mediated the relationship between simulation design characteristics and satisfaction and self-confidence. Conclusion: Simulation educators should apply best practice that enhance teaching efficiency and flow through well-organized simulation designs, nursing students can attain satisfaction and self-confidence through simulation-based education.