With globalization and the rapid evolution of internet, the channels of music communication have become diversified. The communication speed of online music has become faster, and the music-related information is enriched on the internet. However, these positive effects on music communication also increase the complexity of music copyright issues. In face of the great challenges on music copyright issues, this paper takes the online original music works trading platform, namely music trading network as the research object, and uses some mathematical methods, such as statistical theory, power function law and long tail theory, to discuss the copyright protection of the music trading network. Our motivation is to find a way to protect the copyright of original music product so as to stimulate the enthusiasm of musicians, as well as to help find a way to create a healthy original music ecosystem.