Vocal singing and piano accompaniment belong to two different forms of artistic expression, each with its own unique charm. However, in the process of vocal singing, by integrating them with piano accompaniment, the two can be in a harmonious state, bringing a more wonderful audio-visual experience to the audience, and achieving many classic music works. The training of children's chorus is the foundation of singing teaching, and it is also an important means to cultivate children's mastery of singing skills and form good vocal literacy. This article elaborates on the issue of harmony and accuracy in children's vocal choir, the characteristics of children's vocal sounds, and several issues that should be paid attention to in training vocal skills.