At present, there are few cases of Underpass tunnel engineering at home and abroad, and there is a lack of relevant design theory for undercrossing airport airfield. In view of this, based on the project of Shenzhen Bao′an International Airport under which is the shield tunnel of SHZ-9 bid of Guangzhou-Shenzhen inter-city railway, based on the Boussinesq solution and elastic layered theory, the additional stress formula of soil at any depth under aircraft load is derived; based on the derived formula, the law of additional stress value generated by three aircraft loads, Airbus A380, Boeing B-747 and B-777, is analyzed by Matlab, and the position of the maximum vertical stress acting point of three large aircraft is determined; by analyzing the change law at the maximum additional stress point of the three types of large aircrafts in different directions, it is obtained the calculation formulas of the influence range of three large aircraft loads on the shield tunnel in the flight zone at different depth, which has important engineering guiding significance.