Abstract: In order to solve the design problem of abandoned roadway filling system in residual area, taking 3615 working face of Haitian Group as engineering background, we discuss characteristics and system design principle of abandoned roadway filling engineering, focusing on the alternating pulp slurry and continuous supply process, and finally put it into engineering practice. The results show that abandoned roadway filling position is scattered and small quantities, small and medium ground filling station is suitable; high-speed vortex mixer using "bottom pumping" structure, decreased mixing time; dual mixers alternating pulping is helpful to control water-cement ratio and achieve continuous pulp supply; engineering practice show that this ground filling system has a simple structure and reliable operation.