(1) Background: This study investigated the changes in step frequency, walking ability, and standing posture of students with intellectual disabilities by integrating step training into the students’ physical education curriculum; (2) Methods: The centroid formula was used to estimate the geometric center of the students’ bodies in video footage of each participant. Each participant’s stepping frequency per minute was recorded. After training, the teachers involved were interviewed regarding the participants’ everyday activities in school. Each step training session was recorded by two video cameras. Each step training session was observed and photographed by a senior physical education teacher with special education qualifications; (3) Results: The step training increased the stability of the participants’ body axes. The participants’ average steps per minute of the participants significantly improved from 24.200 ± 7.554 to 28.700 ± 8.629. Additionally, despite the students exhibiting anxious behavior (e.g., squeezing their hands and grasping at their clothes) at baseline, the frequency of these behaviors decreased significantly from week 4. Overall, the students’ daily activities, motivation, interpersonal interaction, self-confidence, and anxiety behaviors improved; (4) Conclusions: After the 8-week step program, the participants with intellectual disabilities improved their step frequency, movement stability, ability to perform daily activities, walking speed, motivation, interpersonal interaction, and self-confidence, and they exhibited a lower level of anxiety-related behaviors.