Abstract: The phenomenon of sporadic withering and death of Cotinus coggygria var. cinereus Engl. was investigated continuously in Shimenfang Scenic spot, Shandong Province. The characteristics and number of infected plants at each stage of disease progression were counted in detail, and the epidemic law of disease was summarized. The pathogen was isolated and purified from xylem vascular tissue and then was identified by micromorphological observation, specific primer detection and phylogenetic analysis. The growth of pathogens in different media and carbon sources was observed by plate inoculation. Compared with the known Verticillium dahliae Kleb strain Vd991, the susceptible hosts like cotton and tobacco were inoculated to identify the pathogenicity, and the biomass of the pathogen was detected by qPCR. The results showed that: (1) The wilt of C. coggygria in Shimenfang Scenic spot was caused by V. dahliae, which seriously affected the landscape of red leaves. (2) The occurrence regularity of this disease was summarized: Firstly, it occurred in June every year; then the number of infected plants increased sharply from July to August; finally, a large number of seedlings died in September. The main symptoms include leaf yellowing, xylem and vascular tissue discoloration. (3) The typical conidia, conidiophore and microsclerotia of the were observed by microscopic observation. Specific primer pairs were used to identify the disease as the defoliating phenotype, physiological race2 and mating type MAT1-2-1. Phylogenetic analysis also showed that the pathogen was most closely related to V. dahliae. (4) Growth on different medium and different carbon sources indicated that the disease belonged to the microsclerotium-type strain, which was not strongly dependent on nutrients and had good adaptability. (5) The pathogenicity of this strain was similar to that of the virulent strain Vd991 in both cotton and tobacco, indicating that it had a diverse host range. The highly virulent and widely host-wide V. dahliae strain obtained in this study is not only the main killer of C. coggygria, but also a serious threat to the sustainable development of forest ecosystem due to its potential pathogenicity to other hosts.