Research conclusions: In this paper，the analysis and discussion were made on the commonly － used calculation methods for the impulsive force of falling stone． The calculation of the impulsive force of falling stone was made for the additional hangar tunnel at the tunnel portal of Xiangfan － Chongqing Railway with the subgrade technical manuals method，tunnel technical manuals method，Labiouse method，Kawahara method and Yangqixin method． It was shown that the calculation results obtained by these five methods were almost the same in magnitude． The results obtained by the subgrade technical manuals method and tunnel technical manuals method were a little bigger than the others．However，on consideration of that these two methods had been applied and verified in a large number projects，it was proposed to use the calculation results obtained by these two methods as the design load of the additional hangar tunnel and based on them to make the design．