With the implementation of General Senior High School Mathematics Curriculum Standards (2017 Edition, Revised in 2020), probability and statistics, as important carriers of the core mathematical competencies “mathematical modeling” and “data analysis,” have increasingly highlighted their educational value. By summarizing the historical evolution of probability and statistics thinking and combining with teaching practice cases, this study explores its unique role in cultivating students’ core mathematical competencies. The research proposes a project-based teaching strategy relying on real scenarios and empowered by technology. Through cases, it demonstrates how to use modern educational technology to realize the whole-process exploration of data collection, model construction, and conclusion verification, so as to promote the transformation of middle school probability and statistics teaching from knowledge imparting to competency development, and provide a practical reference for curriculum reform.