Abstract: The elevated jet fire trucks are important fire equipment products; when the folding arm is fully expanded, the equivalent force point and the span between the slewing center will reach tens of meters, so that the impact of the water cannon and wind will have a greater impact on the stability of the vehicle, which will lead to the vehicle tilting forward or overturning in serious cases. In order to avoid dangerous working conditions, the 72m elevated jet truck is taken as the object in this paper, fully considering the influence of various factors, C++ programming is carried out, the equivalent action point and action force are calculated according to the relevant standards. Finally, the force of each outrigger is calculated, and the stability tests are carried out according to the national standard and the combined force circle analysis. It provides a certain reference for the same type of analytical calculation work.