The invention provides a multi-level doped PbTe-based thermoelectric material and a preparation method thereof. A molecular formula of the multi-level doped PbTe-based thermoelectric material is InxPb1-xTe1-yAy, wherein A is Cl, Br, I, Ga or Al; x is greater than 0 and less than or equal to 0.02; and y is greater than 0 and less than or equal to 0.03. According to the technical scheme, simultaneous doping of deep and shallow levels is adopted; carrier concentration at a low temperature is increased by utilizing shallow level doping; carrier concentration at a high temperature is increased by utilizing deep level doping; an ambipolar diffusion temperature is increased; and the thermoelectric material with a high thermoelectric merit figure within a wide temperature range is finally obtained. The thermoelectric efficiency of the material is improved.