To study the effects of diesel fuel blended with polyoxymethylene dimethyl ethers (PODEn) on the emission characteristics of a diesel engine, relevant tests were conducted on a Yunnei Power 2102QB diesel engine. The PODEn were blended with diesel fuel at four different ratios (mass fractions of 10%, 20%, 30%, and 50%). Results showed that the addition of PODEn improved the emissions of HC, CO and smoke effectively. With an increase of PODEn blending ratio, the NOx emission increased gradually, with the maximum increase of 35.3% at the speed of 1500 r/min. The NOx emission of the PODEn/diesel blended fuel should be improved by using EGR or exhaust post-processing device. The HC and CO emissions decreased significantly, with the maximum reduction of 60.1% and 85.2%, respectively. The smoke emission was improved significantly by blending PODEn at various conditions. At high load conditions, the opacity could be reduced by more than 50% when the PODEn blending ratio was 20%.