The present disclosure provides a lower box body, a battery box and a vehicle, the lower box body comprises a base body, a first protecting assembly, a mounting hole. The base body comprises a bottom plate portion, a side plate portion, eave portions. The first protecting assembly is provided at outside of the base body, fixed to the base body and is attached to the eave portion. The mounting hole penetrates the eave portion and the first protecting assembly. The first protecting assembly improves the entirety structural strength of the lower box. Because the mounting hole is formed by penetrating the eave portion and the first protecting assembly, the structural stability of the mounting location of the lower box body is improved, thereby making the mounting location of the lower box body not be prone to be deformed or damaged when the battery box is subjected to the external force.