The train derailed at 10:30am local time after hitting debris from a landslide that was on the track while it was approaching Rongjiang county, Guizhou province, CCTV said.
The train conductor died in hospital, CCTV said. One crew member and seven passengers were injured.
The remaining 136 passengers were safely evacuated, and the incident is under investigation, CCTV said.
No major incidents have been reported on the network since 2011, when 40 people were killed and nearly 200 others injured after a high-speed train was struck from behind by another train near Wenzhou, Zhejiang province.