Method for judging top coal flow state of top plate at tail part of fully mechanized caving mining bracket

The invention provides a fully-mechanized caving mining support tail top plate top coal flow state discrimination method, which comprises the following steps: based on measurement parameters of fully-mechanized caving face top coal and direct top rock strata, reasonably calculating and designing a hydraulic support model reduced according to a certain proportion, and arranging a vibration detection sensor on a model tail beam; the vibration frequency detection module is used for detecting vibration frequency signals F coal-simulation and F rock-simulation of the coal and rock broken particle collision hydraulic support model; monitoring vibration frequency signals F coal and F rock of a collision hydraulic support in the process of top coal and direct roof caving in field mining; processing and calculating the two monitoring values, and then according to the duration t1 of the vibration frequency signal recorded on site at the F coal, the time point t2 when the signal is abrupt change and the duration delta t