The invention relates to a grate-type ball mill and a grid plate for the ball mill. The grate-type ball mill comprises a cylinder and a speed reducer, one end of the speed reducer is connected with a motor through a coupler I, the other end of the speed reducer is connected with a small transmission gear through a coupler II, the small transmission gear is connected with a large turning gear on a hollow shaft through a sprocket, the cylinder is arranged on the hollow shaft, one end of the cylinder is connected with a main bearing, the main bearing is connected with a feeding portion, and a discharging portion opposite to the feeding portion is arranged on the cylinder. Ore grinding capacity is improved, firmness and non-falling are ensured in the running process of the ball mill, bolts are prevented from loosening or breaking due to cyclic stress, the ball mill is long in service life, low in grid hole abrasion and not easy to block, working efficiency is improved, ore pulp backflow is not easily generated, and the ore discharge efficiency and the service performance of the ball mill are improved.