Abstract The treehopper genus Tricentrus is a widespread group of insects, characterized by typical spines and, in some species, sexually dimorphic suprahumeral horns. With 238 described species worldwide, Tricentrus represents the most species-rich genus in the subfamily Centrotinae. Currently, 72 species are documented in China, yet the phylogenetic relationships and evolutionary history of this genus remain unknown. Here, we use an integrative approach to characterize and describe these treehoppers based on materials collected from China. We name three new species: Tricentrus allochrous Li & Chen sp. nov . and Tricentrus pianmaensis Li & Chen sp. nov . from Yunnan, Tricentrus dexingensis Li & Chen sp. nov . from Xizang, with the revision of one synonym. Combined analysis morphological comparisons, species delimitation and phylogeny reliably separate these new species from known species, and sexual dimorphism with suprahumeral horns in three species is reported for the first time. Divergence time estimation indicates that the Tricentrus differentiated during the Early Cretaceous (110.41 Mya). Ancestral state reconstruction reveals that the most recent common ancestor possessed suprahumeral horns in both sexes and exhibited a short tubular pygofer apex. Our analyses demonstrate four evolutionary transformations in pygofer apex morphology and seven distinct transitions in suprahumeral horn development. These morphological diversifications likely resulted from multiple mechanisms, including sexual selection, life history strategies with associated behavioral adaptations, and incomplete lineage sorting.