Aiming at soft coal and rock mass characteristics of low strength, poor cementation and mud formed in case of water,anchoring force of normal anchor is low and decay speed is fast.The relationship between anchoring force and displacement of soft coal and rock under different anchoring conditions is analyzed by using self-developed anchored hole bottom-wing inverted wedge reaming device.Experimental results show that anchoring force and displacement curve of the front anchor of the "mutation point" in two anchoring states coincide with the displacement curve,"mutation point" after normal anchoring state of the residual anchor moment of attenuation, attenuation to almost 0, and residual anchoring force of the residual anchoring force is small and the residual anchoring force is greater than decoupling force.The maximum anchoring force of the hole anchoring at the "mutation point" in the anchoring state is an average increase of 2.8 in the normal anchorage state.The anchor section of the soft coal and rock mass is interface of anchor and the wall in hole, and anchorage agent is crushed to wall of the inverted wedge.And bore hole anchorage stress process can be divided into initial stress stage,transition section and expanding anchorage segment of plastic zone-expansion phase three stages, analyzed by reaming anchor anchoring force attenuation under condition of law, to solve the soft coal and rock mass roadway bolting technology difficult problem to provide important reference.