With the continuous expansion of technological application scenarios, the cultivation of computational thinking urgently needs to shift from the single information technology teaching to interdisciplinary teaching. Against this backdrop, the paper first analyzed the logical origin of computational thinking integrated into project-based teaching in mathematics from three aspects of theoretical foundation, practical demands, and practical implementations. Subsequently, by combining the key elements and key paths of computational thinking integrated into project-based teaching in mathematics, this paper constructed a theoretical model of computational thinking integrated into project-based teaching in mathematics. In this model, the content layer focused on integrating computational thinking concepts into mathematical subject knowledge; the process layer emphasized promoting mathematical problem-solving through computational thinking practice; and the goal layer aimed to achieve the collaborative cultivation of computational thinking and mathematical thinking. Finally, based on this theoretical model, the paper designed and implemented a case teaching titled “Automatic Tile Laying”. The implementation effects showed that the case teaching improved students’ computational thinking levels, and the developmental trajectory of students’ computational thinking aligned with teaching expectations, and students had a good learning experience and significantly enhanced learning interest. The research in this paper not only provided a teaching paradigm for computational thinking integrated into project-based teaching in mathematics, but also offered a valuable reference for exploring the educational model of integrating interdisciplinary thinking.