Against the backdrop of the Emerging Engineering Education (3E) Construction, this study addresses prevalent issues in Soil Mechanics courses, including fragmented knowledge, polarized academic performance, and low teaching efficiency. It constructs a Trinity Integration Teaching Model encompassing "curriculum ideology and politics, online platform, and knowledge mapping," and conducts an empirical analysis using students from the Civil Engineering program at a university in Tianjin (cohorts 2020-2022) as the sample. The findings reveal: (1) The model significantly optimizes course effectiveness. The 2022 cohort achieved an average score of 75.11, representing an 18.5% increase compared to the 2020 cohort. The standard deviation decreased from 18.52 to 13.47, and the coefficient of variation dropped by 11.3 percentage points, signifying a transition from a "low average + high dispersion" to a "moderate average + low dispersion" profile. (2) The synergistic mechanism drives dual improvements in educational equity and learning efficacy: curriculum ideology and politics strengthen value guidance, the online platform overcomes time constraints, and knowledge mapping constructs a systematic cognitive framework, leading to marked progress among low-performing students. (3) Based on data fitting, the 2023 cohort"s average score is predicted to exceed 80, with the standard deviation approaching 12, validating the model"s sustainability. This provides a replicable, structured reform pathway for similar courses within the Emerging Engineering Education framework.