at present, the product quality that tire building machine presses tire is not ideal. The phenomenon that the tread isn’t pressed solidly often appears. Through analysis, the main reasons of this problem are those the actual rolling curve doesn’t accord with ideal curve enough, and roller pressure is unstable, pressure fluctuations are large. Therefore, ensuring the basic structure of institution is unchanged, this paper adopts optimization technique to calculate the size of planar linkage institutions and determine the best design result. It makes the moving point from the planar linkage institutions accord with tire section curve best. The article cites example of the engineering design, demonstrating the superiority of the new design method fully.