The invention relates to a check method and a check device for the ultimate strength of a yaw brake disc of a fan, and belongs to the technical field of wind power generation. The method comprises the steps of firstly building a geometric model comprising a fan yaw brake load transfer path, then importing the model into finite element analysis software to perform grid partition, setting a connection structure load and a boundary condition, building a node at a central position of a flange on the top of a tower, connecting the node with a flange at the front end of a main frame via a rigid beam unit, applying a limiting condition load to the central position of the flange on the top of the power, transferring the load to the main frame via the rigid beam unit, and transferring the load to the yaw brake disc via a yaw brake caliper, thus achieving accurate simulation of a stress relation of the yaw brake disc. According to the method provided by the invention, the acquired stress size and dangerous position of the yaw brake disc are higher in accuracy and accordant with the actual stress relation of the yaw brake disc, and accurate check on the ultimate strength of the yaw brake disc of the fan can be achieved.