In the field of music, performers often suffer from stage anxiety. This study focuses on comparing the effects of practicing in a "practice room" and practicing in an "outdoor open space" such as a park or street with a large flow of people on stage anxiety. The aim of this study is to explore the impact of different practice scenarios on stage anxiety, verify the hypothesis that "open-space practice is more conducive to reducing stage anxiety", and thereby provide a solid basis for performers to improve their stage anxiety issues. This study employed a single-subject pretest-posttest experimental design. Music learners were selected to practice two pieces of the same difficulty level for the same duration in two different settings: a piano room and a park with a high volume of people. The first month was spent practicing in the piano room, and the second month in the park. At the end of each month, a stage performance was held. To measure the anxiety levels of the performers, we used the core questions of the Kenny Music Performance Anxiety Inventory (K-MPAI), which were filled out before each performance. Heart rates were measured five minutes before the performance using smartwatches. Audio recordings were made with mobile phones to count the number of wrong notes. Professional teachers were also invited to evaluate the performances. It was found through research that the anxiety level of performers practicing in the park was significantly lower than that of those practicing in the music room. Their heart rates and the number of mistakes were also lower when practicing in the park. Moreover, professional teachers also observed that performers were more relaxed on stage after practicing in the park. This study demonstrates that by incorporating regular practice sessions in outdoor open spaces such as parks, in addition to regular practice in conventional practice rooms, musicians can effectively alleviate pre-performance physiological tension, psychological anxiety, and performance errors, thereby significantly enhancing the integrity and stability of their stage performances. Such diverse scene training can bring about comprehensive improvements from heart rate and mood to actual performance behaviors, further strengthening the musicians' adaptability to different environments and overall presentation quality.