The utility model provides a top of roadway board unstability graded warning device, belongs to top of roadway board supporting technology field. Top of roadway board unstability graded warning device includes steel wire, hollow anchor rope, displacement sensor and early warning device, rock -entering in situ and anchor are inserted on the top of roadway board to hollow anchor rope, and the steel wire lies in the hollow structure of hollow anchor rope, and the one end of steel wire and hollow anchor rope to lie in the intraformational one end of rock fixed, the other end stretches out from the anchor end of hollow anchor rope, the end that stretches out of steel wire is connected with displacement sensor, displacement sensor and early warning device link to each other. The period that this top of roadway board unstability graded warning device located when can timely feedback top of roadway board warping, make the corresponding measure that prevents to the hidden danger problem that probably appears, and the device can accomplish the installation at the in -process to roadway support, need not to use the rig to drill in addition and install, practiced thrift a large amount of time and cost.