Unmanned aerial vehicle and fire fighting truck

The utility model discloses an unmanned aerial vehicle and a fire fighting truck, and relates to the technical field of unmanned aerial vehicles and fire fighting trucks for fire fighting, the unmanned aerial vehicle comprises an unmanned aerial vehicle body and at least two rotor arms, the unmanned aerial vehicle body is provided with first connecting parts which are distributed along the circumferential direction and correspond to the rotor arms in number, a first connecting part is arranged at one end of each rotor arm, a second connecting part is arranged at one end of each rotor arm, the first connecting parts are hinged to the second connecting parts so that the rotor arms can rotate relative to the unmanned aerial vehicle body to switch the folding and unfolding states of the rotor arms, and the first connecting parts and the second connecting parts can be connected through a locking mechanism. And the locking mechanism is used for locking the unfolding state of the rotor arm. The fire fighting truck c