A wet-type disc-type coarse grain preselector belongs to the technical field of mineral selecting equipment and is used for wet-type preselection of strong magnetic minerals. The technical scheme is as follows: the wet-type disc-type coarse grain preselector comprises a plurality of magnetic discs, a sucking disc, a rotating shaft, a motor and a material distributing plate, wherein the magnetic discs are fixedly arranged in parallel; through holes are formed in the centers of the magnetic discs; the rotating shaft penetrates through the through holes; one side of the disc surface of each magnetic disc is a magnetic zone, and the other side of the disc surface of each magnetic disc is a non-magnetic zone; magnetic blocks are installed on the disc surfaces and the disc edges of the magnetic zones; the sucking disc is made of an alloy iron sheet; the sucking disc is sleeved on the periphery of the magnetic discs; the center of the sucking disc is connected with the rotating shaft; the rotating shaft is connected with the motor; the material distributing plate is arranged above the outer sides of the magnetic zones of the magnetic discs; a mineral feeding belt is arranged below the material distributing plate; and a concentrate discharging port and a tailing discharging port are formed below the magnetic discs respectively. Compared with a drum magnetic separator with the same outer shape and size, the wet-type disc-type coarse grain preselector has the advantages that the working area is 2.6 times larger; the preselecting amount is 6 times higher; the adapted grain size is improved to 30-0 mm; and part of coarse grains with the diameter of 80 mm can be preselected without causing blockage of equipment.