Vegetation survey is the most common method to study the characteristics of urban surface vegetation communities, and it is also the method basis for further research on urban ecology and botany. Based on the different purposes, different scales, and different landforms of vegetation surveys, the methods selected by the investigators are also different. In this study, the purpose of the survey is to study the characteristics of dominant species at the land scale of Shenzhen. High-resolution remote sensing satellite images and ground field survey were used to conduct a rapid census of the vegetation in the land area of Shenzhen. The results showed that: (1) There were altogether 182 families, 858 genera, and 1,443 species of dominant plants in the land area of Shenzhen, among which angiosperms were the dominant plants, accounting for 94.66% of the total species. (2) Judging from their floristic distribution, the dominant seed plant families in the Shenzhen territories belonged to 14 distribution areas. The geographical constituents of the plants were complex, and the tropical floristic attributes were very apparent. (3) 83,834 non-adjacent textural heterogeneous cluster patches were classified into 741 different vegetation groups, 12 vegetation types, and 3 vegetation types (those of the south subtropical evergreen broad-leaved forests, south subtropical grassland, and south subtropical shrubland were dominant). (4) According to the statistical analysis, there were more abundant vegetation groups in the suburbs than in urban areas. There were 608 vegetation groups in the suburbs and 569 vegetation groups in urban areas, with 437 vegetation groups in common. There was no obvious difference in the number of dominant plant families, genera, and species between the urban and suburban areas. (5) By comparing the list of invasive plants in China, 258 alien invasive plants were screened in Shenzhen, which were distributed across 62 families and 200 genera, mainly in the leguminous, composite, and gramineous families. Finally, according to the process and results of this rapid vegetation survey, suggestions for the improvement of urban vegetation management and vegetation surveys were given, aiming to provide a scientific basis for future urban policy formulation and planning implementation. In addition, in order to verify the scientificity of the survey method and the correctness of the survey results, the results of this article were compared with the survey results of two University Investigation Team using traditional long-period methods. This result contains 88.5% of dominant species in the survey results of the University Investigation Team, which reflects the effectiveness of this method in the census of dominant plant species.