Bi2Te3 has been the most high-performance thermoelectric (TE) cooling material since the 1960s. To date, the TE property of n-type Bi2Te3-based is still lower than p-type Bi2Te3-based material. Therefore, n-type materials attract a lot of attention and effort. Herein, according to the light impurity doping and entropy engineering, the TE performance of n-type Bi2Te3 was improved. Lightly doping of Ag, Cu, S, Se elements in Bi2Te3 alloy conduces to improve the carrier mobility without affected the band structure of Bi2Te3. In particular, an entropy engineering approach by using the doping of four elements (Ag, Cu, S, Se) is being adopted to reduce the thermal conductivity of the n-type Bi2Te3-based. Therefore, the lightly doped (Ag, Cu, S, Se)-Bi2Te3 alloy achieves high power factor and low thermal conductivity, which improves the TE performance of n-type Bi2Te3.