The invention relates to a liquefied petroleum gas steel cylinder volume determination and liquid spray lubrication apparatus. The apparatus comprises a volume measurement liquid spray rod, a steel cylinder lifting platform, a steel cylinder positioning apparatus and an elevating control apparatus used for the volume measurement liquid spray rod, wherein the volume measurement liquid spray rod is disposed above the steel cylinder lifting platform, one side of the volume measurement liquid spray rod is provided with an induction switch, and the top end of the volume measurement liquid spray rod is provided with an induction member capable of emitting unqualified detection signals; one side of the elevating control apparatus is provided with a first magnetic switch used for controlling the steel cylinder positioning apparatus to be loosened and a second magnetic switch used for controlling a bleeder valve to be open to enable a lubrication liquid in a reservoir to go into a liquid storage pipe connected with the volume measurement liquid spray rod; and the liquid storage pipe is connected with a compression gas source through a charge valve. According to the invention, when the volume of a liquefied petroleum gas steel cylinder is determined, personnel operation is unnecessary, the work efficiency and the technical quality are improved, operators are reduced, and the problems of no guarantee of quality and low efficiency which are caused by conventional manual determination are solved.