The Changbai Waterfall at the mouth of Tianchi Lake (Heaven Lake) is a tourism resort, with a mountainclimbing path to the water surface of the Tianchi Lake. There are obvious unconformity interfaces, weathering crust and faults. Steep cliffs with welldeveloped joints may cause rock avalanche, bl ock stripping and mudflow disasters. The paper put fowards a practical opionion for preventing and controlling geologic a l hazards and protecting the natural scenery.