Abstract: BSY-2 combine drill was designed to be hitched to two wheel walking tractor (6～8 hp) and to apply water, grain and fertilizer in one pass. One of the key points was the design of the land gauging parallel-link hitch mechanisms. Based on the force balance and the Lagranage's Equation analyses, a numerical modeling of the mechanism was established and the structural parameters were optimized by computer programs. The manufactured drills were tested in mountainous areas of west Shanxi Province, the drafting performance of the mechanism was satisfactory and the sowing depth was stable.