The invention provides a steel disc used for manufacturing a tread pattern, a steel disc installing method and a tire mold and relates to the technical field of tire manufacturing. The steel disc formanufacturing the tread pattern comprises a cutting edge part, a fixing part and at least one fixing piece, wherein the fixing pieces are arranged on the fixing part. Each fixing piece comprises a fixing segment and a connecting segment, wherein the connecting segment is connected with the fixing part, the fixing segment is suspended, and the fixing pieces and the fixing part are arranged in a dipangle manner. In the technical scheme, due to the fact that the fixing pieces and the fixing part are arranged in the dip angle manner, after the fixing segments are embedded into the casting mold, the steel disc achieves the anti-disengaging effect at multiple angles, and the connecting fastness of the steel disc is improved.