The invention discloses a high-gas-sensitivity multi-element-compounding metal oxide, a preparing method and an application. The preparing method includes the steps that metal ions corresponding to p-type semiconductor metal oxide, metal ions corresponding to n-type semiconductor metal oxide and doped metal ions are mixed, a coordination agent is added, precipitating, aging, drying and roasting are carried out, and the high-gas-sensitivity multi-element-compounding metal oxide is obtained. The valence state of doped metal is lower than the valence state of p-type semiconductor metal or the valence state of the doped metal is higher than the valence state of n-type semiconductor metal. The compounded metal oxide has p-n junctions capable of improving sensitivity and responsiveness; meanwhile, a proper amount of doping treatment is carried out, and the ternary or quaternary compounding metal oxide is formed; the structure of the multi-element-metal-compounding hydroxyl compound is adjusted and controlled by adding the coordination agent, and therefore the structure of a metal-compounding oxide material is controllable.