This paper focuses on the application and development of “human-computer interaction” (HCI) in online education by briefly outlining the concept of human-computer interaction mode and the development of human-computer interaction technology. According to analysis, from 2010 to 2020, the total revenue of the global digital music industry will first decline and then increase, with the total revenue of the global digital music industry reaching US$21.5 billion in 2020, an increase of 7.7% year-on-year. The role of the HCI model in music education is discussed. A new portfolio of HCI online music applications is proposed and existing HCI online music teaching software is analysed. This is followed by a study of 'Little leaf Music Education' using HCI as an entry point. A participatory action research approach was used to develop a HCI course rating scale. A survey method was used to conduct the study and 66.67% of the 12 individuals surveyed attended the sessions. The four students who were not fully enrolled had an attendance rate of 60% or more. This demonstrates that the students were not resistant to the HCI 'Little Leaf Music Education'. Subsequent research into after-school work revealed that students' offline work submission rates under the HCI system were as high as 90%. Assignment pass rates were as high as 90%. Finally, a mock exam found that 75% of students scored well on the exams. In addition, the HCI classroom satisfaction and teacher satisfaction surveys found that the overall satisfaction rate for both was 100%. The HCI model has enriched the possibilities of hands-on music teaching activities and has effectively guided the development of students' imagination and creativity. This also provides strong data to support and guide the future use and development of HCI in online education.