Objective To prepare the specific monoclonal antibody (mAb) against E domain III (ED3) of duck Tembusu virus (DTMUV) and explore its neutralization activity. Methods The ED3 gene was amplified by using reverse transcription PCR according to the genome of the DTMUV AH-F10 strain. Then, the recombinant expression vector pET32a-ED3 was constructed and transformed into E.coli Rosetta. The ED3 protein was expressed and purified by nickel column affinity chromatography. After the recombinant ED3 protein was identified by SDS-PAGE and Western blot analysis, the BALB/c mice were immunized subcutaneously three times. The splenocytes of the immunized mice were hybridized with Sp2/0 myeloma cells, and the hybridization was screened by the limiting dilution method. The specificity and sensitivity of the antibody were identified by indirect immuno-fluorescent assay and Western blot analysis. Subsequently, antibody titers were determined by ELISA. Finally, this study titrated the neutralization titers of the antibodies on DTMUV-infected BHK-21 cells. Results The ED3 protein was successfully prepared and purified using the prokaryotic expression system. Three strains of monoclonal antibodies named B9D10C7, B9D7B8G10 and B9D7B8F11 were prepared. Their subtypes were IgG1, IgG2a and IgG2b, respectively. The titers of monoclonal antibody ascites can reach 1:51 200, and they could specifically recognize the E protein of DTMUV. Neutralization test showed that they had a certain neutralizing activities. Conclusion The monoclonal antibodies against ED3 protein of DTMUV are successfully prepared.