Middle-waisted bidirectional filling and mining method under canopy guard in thick and great metal mine in sea bed

The invention discloses a middle-waisted bidirectional filling and mining method under canopy guard in a thick and great metal mine in sea bed, which is characterized in that a safety isolating layer is preserved between an ore body and the sea bed; the ore body is divided into an upper part and a lower part at the middle waist in the altitude direction; the altitude from the middle waist position to the sea bed sea mud is 100-150m; stoping is carried out from the middle waist position of the ore body, wherein the upper part adopts upstroke mining and the lower part adopts downstroke mining; a rock trackless quasi-upward slicing cemented method with a regular post pillar is adopted in the upstroke mining method; a rock trackless quasi-ordinary slicing cemented method is adopted in the downstroke mining; the gob in the stope is filled with filling materials. The invention is characterized by having high safety of mining, little loss of resources, high degree of mechanism, low labor intensity, great production capacity, short stoping time, low mining settlement and the like.