To address challenges in fluid mechanics experimental teaching for the Building Environment and Energy Engineering (BESE) major—namely, limited experimental resources, poor visualization of micro-phenomena, and low student motivation—a three-stage progressive virtual-physical integrated teaching model (virtual pre-training, in-class deepening, and physical verification) was proposed based on constructivist learning theory and self-determination theory. The FluidLab game-based virtual simulation platform was developed as the primary vehicle for implementation. This platform deconstructs the fluid mechanics knowledge system into 44 progressive challenge tasks and incorporates gamified incentive mechanisms—such as point systems, leaderboards, and achievement badges—thereby enabling the dynamic visualization and interactive exploration of abstract concepts like the Bernoulli effect, laminar-turbulent transition, and boundary-layer separation. A teaching practice was conducted involving 142 BESE students, and their performance was compared with that of a historical control group from previous cohorts who did not use the platform. Results demonstrate that the experimental group scored significantly higher on fluid mechanics questions in the final examination. Furthermore, over 85% of the students reported that the challenge-based mode effectively stimulated their learning motivation, and 92% agreed that dynamic visualization facilitated their understanding of abstract concepts. Notably, virtual pre-training significantly reduced the cognitive load of subsequent physical experiments and promoted the positive transfer of learning experiences. This model offers practical insights for the reform of engineering experimental teaching.