Definitely try to get some data from Dalia Kirschbaum and the global inventory she has prepared.
I am not aware of any national scale inventory and if it exists, I doubt that you can simply get your hands on it. You can try contacting the Geological Survey of China http://en.cgs.gov.cn/
The landslide group at the Chengdu University of Technology could also be a potential source.
From my experience in China, the best source for data is guanxi (關係). You can try contacting the authors of papers dealing with landslides in Yunnan and see if you can get data from them. You should probably offer something in return, e.g. a research cooperation or a role in a project.