Repetition scatters in narrative, and it shows the heterogeneous isomorphism with differences integrated with repetitions. Due to the shared textuality thinking between inherent musicality of oral literature and polyphony, canon model with its contrapuntal compositional technique is universally found in the compositional mechanism of oral literature, and creates a narration of repetition based on imitation under temporal principle and counterpoint under spatial principle. Within a single text and across multiple texts, canon model may take the forms of parallel canon, mirror canon and endless canon based on the development of plot. The former two forms can further be divided into subtypes Ⅰ, Ⅱ, Ⅲ and Ⅳ based onconfigurations of characters, events and results, with the subtypes overlapping in different dimensions. The repetitive mode in canon composition sheds light to the understanding and construction of conventional performance structure of oral literature, and apart from exploring the compositional principles, it also points to the interdisciplinary research on folk literature and musicology.