Music co-creation is of great significance for children's music enlightenment education. It helps children cultivate music interest and aesthetics and develop interpersonal skills. Intersubjectivity emphasizes the existence of mutual subjects in interpersonal relations. It can provide more effective ideas for the interaction and communication between people and tangibles in children's music co-creation activities. The composition of subjects in children's music co-creation activities was analyzed. The process of participation and design in children's music co-creation activities was deconstructed and analyzed. It was concluded that the experience of music co-creation could be strengthened from the three aspects of "triggering common motivation", "promoting coordinated operation" and "encouraging dynamic adjustment". Based on the analysis of music co-creation cases at home and abroad, the design strategies of music co-creation tangibles from the perspective of intersubjectivity were concluded, including "the design of target, task and feedback", "the setting of mechanism, form and model evelopment of digitalization can be brought into full play in terms of promoting music education and prosocial behavior.