Three-dimensional vegetation volume is a comprehensive indicator to characterize the ecological benefits of urban vegetation. In this study, taking the Cinnamomum camphora woodland in Pujiang Country Park in Shanghai, the research calculated and compared the three-dimensional vegetation volume of Cinnamomum camphora in the research area by using the UAV lidar method and the traditional measured estimation method. The study found that: (1) Compared with the traditional measurement and estimation methods, the UAV lidar method can significantly improve the accuracy and efficiency of measuring the three-dimensional vegetation volume of vegetation. (2) The total three-dimensional vegetation volume of the camphor-like land in Shanghai Pujiang Country Park is 2 936.55 m3, the average three-dimensional green density is 2.17 m3/m2, and the linear correlation between the three-dimensional vegetation volume amount and the crown area of the single wood is significant. Therefore, the study can provide a method reference for rapidly estimating urban vegetation’s three-dimensional vegetation volume.