The situation of vehicle passed under the conditions of limited vehicle running speed and vehicle passing is simulated. The transportation capacity of singlelane and twinlane are analyzed by means of mathematical deduction method. The layout of the inclined shaft crosssection is analyzed. The results show that: 1) The vehicle passing capacity of twinlane inclined shaft is far larger than that of singlelane inclined shaft. 2) The crosssection size of singlelane inclined shaft and that of twinlane inclined shaft are proposed by making analysis on relevant parameters.