Automobile exhaust system and off-road fire truck

The utility model relates to an automobile exhaust system and a cross-country fire fighting truck, the automobile exhaust system is applied to the fire fighting truck, the automobile exhaust system is arranged in a gap between an automobile head and a compartment and is connected with an exhaust main pipe, and the exhaust main pipe extends backwards from the bottom of the automobile head and is bent upwards between the automobile head and the compartment. The exhaust system comprises at least two exhaust branch units, and each exhaust branch unit comprises a silencer and a three-way catalyst which are independently arranged. The arrangement position and the ventilation capacity of the exhaust system are improved, so that heat in the exhaust system is dissipated to the surrounding environment to the maximum extent, the temperature around a wiring harness, a gas path and an oil path at the bottom of a vehicle is effectively reduced, and the reliability is improved. 本申请涉及一种汽车排气系统及越野消防车，其中汽车排气系统应用于消防车上，所述汽车排气系统设置