The invention establishes a method for in-vitro amplification of a CD8+T cell and a cell subset of the CD8+T cell. By adding a TLR1 / 2 agonist, a TLR2 / 6 agonist and a TLR5 agonist into an in-vitro culture system for conventionally culturing and amplifying the CD8+T cell or conjunctively utilizing the agonists, the amplification efficiency of the CD8+T cell can be remarkably improved; besides, by utilizing a TLC agonist, the functional CD8+T cell subsets which are difficult to amplify under a conventional culture condition are amplified, such as PD-1+CD8+T cells and TEM CD8+T cells; and the CD8+T cells and the functional cell subsets can be rapidly and largely propagated under the common and continuous stimulation of a TLRs agonist, recombinant cell factors IL-2, IL-7 and IL-15, an anti-human CD3 antibody and anti-human CD28 antibody coated magnetic beads.