The invention discloses a mining method of a thin minor ore body, which comprises the steps of ore recovery and goaf filling, which are alternatively circularly performed from bottom to top in a horizontal layering manner, propelling is performed along with a work surface, lime, loess, dead rock and the like are adopted and mixed layer by layer to fill a goaf, a filling body supports hanging wall and heading wall surrounding rocks, and serves as a work platform of upper layering recovery and ore removal, the ore is conveyed to an ore chute with a mechanical method, spallation ore removal of each recovery spallation step length and the filling procedure of the goaf are performed alternatively, when the uppermost horizontal layer of a chamber is recovered, mechanical and manual fill tightening are performed. The method solves the problem of discharge of tunneled dead rocks, effectively processes the goaf, prevents surface subsidence, accords with requirements of circular economic development and green ore construction. Compared with a shallow hole shrinkage method, the mining method has the advantages of improving ore recovery rate, reducing ore dilution rate and improving ore removal grade and ore removal efficiency through production practice.