Abstract: Aiming at the problem of triangular coal loss and resource waste caused by boundary triangle coal and irregular block segments,taking the No.81308 fully-mechanized top coal caving mining face of Baode Coal Mine as the engineering background,and based on the theory of boundary triangular coal rotary mining technology,and combined with geological conditions and current status of working face,the key technology of tail entry layout,equipment lap joint,mining technology and roof control in triangular coal mining was studied.The research results show that：①The segmented folding line method is used to design the rotating section of the tail entry,which reduces the change of the working face length.②The front scraper conveyor is equipped with a conveyor slot in advance and the end bracket and the loader are offset by 5° to the auxiliary,which solves the problem of overlapping the front and rear scraper conveyors with the transfer machine.③Adopting the one-way coal cutting process of cutting the triangle coal chamfering in the tail,achieving continuous advancement of the working face.④Adopting the head support without coal top coal caving mining process and equipped with single props to ensure the stability of the roof near the rotating center.Through the application of key technologies for rotary mining in fully mechanized top coal caving mining face,the boundary triangle coal was successfully recovered.