In this paper, we first systematically sorted out the characteristics of pop singing and musical theater singing and explored the generation of emotion and melody application of pop singing in musical theater singing. Then, the gray GM(1,1) model is analyzed, and a gray data mining model based on data analysis is constructed to predict the application of pop singing in combination with the data mining model under data analysis. Finally, the prediction analysis was conducted to use characterization, timbre and style in pop singing, respectively. The results showed that the score of character building was 90, and the errors between the predicted and actual values of timbre and style were between ±0.1 and ±1, respectively, which were within an acceptable range.