The invention provides a division and determination method for a deformation stage of surrounding rocks in a tunnel of a fully mechanized caving mining, and relates to the technical field of mine safety. The method comprises the following steps of: firstly, dividing the area, which is formed in front of the working face after mining, into a plastic zone and an elastic zone; and calculating the vertical stress of the plastic zone, thereby obtaining the peak position of the lead abutment pressure. Then, dividing the deformation stage of the surrounding rocks in tunnel into an elastic deformationzone and a plastic deformation zone, by taking the peak position of the lead abutment pressure as a boundary. Dividing the plastic zone into a failure zone and a limit equilibrium zone, by taking theintersection as a boundary, which is the intersection of the curve of lead abutment pressure and the stress line of the original rock. Finally, arranging an observation station on the working surfaceto observe the lead abutment pressure; and monitoring and organizing the date of the lead abutment pressure; thereby determining the deformation stage of the surrounding rocks in tunnel. According tothe division and the determination method for the deformation stage of surrounding rocks in the tunnel of the fully mechanized caving mining, the deformation stage of the tunnel can be accurately divided according to the lead abutment pressure; and the theoretical support is provided for the advanced support for the tunnel and the control of the deformation of surrounding rocks in the tunnel.