Abstract: According to the complex condition of broken roof under extreme close repetition mining, taking the determination of 4303 mechanized mining face in the fourth panel as the engineering background, firstly, the support strength was determined as 587.25kPa by theoretical analysis separately, and the type of ZY5000/12/26D support was developedbyVisual R & D program. Finally, from aspects of support resistance, operation characteristics, Initial bracing force, coal wall slate and roof fall, the suitability of the support was verified by engineering practice. The application of the support is good and itprovides reference for the design of supportin similarcondition.