Abstract:Both tension fracture and shear fracture is the dominant mechanic mechanism for perilous rock in tension-shear fracture to rupture.On the basis of assumption of plane strain,the authors make testing research on development process of perilous rock in tension-shear fracture through model testing in laboratory.Some important results are as following: Damage and fracture of the perilous rock under action of loads is developing gradually from foot area to top area of cliff.Perilous and fracture of the perilous rock is in abruption.Control fissure manifests tension rupture in initial stage under loads while become shear rupture when end area of control fissure extend certain site to bottom of the perilous rock,etc.These studies provide some important testing evidences about researching on development mechanism of perilous rock in the future.