Pressure-wave supercharger (PWS) is one technical way to boost the engine intake air pressure. PWS has several advantages such as less emission (especially NOx emission), rapid response when load changes, higher torque even at low engine speed. In this research a 493 diesel engine is charged by a pressure-wave supercharger (PWS). The emission performance of the PWS diesel engine is mainly investigated. Together with experimental test, the CFD simulation is completed basing on a 3D model of the PWS rotor channel. The CFD simulation results show that the inner EGR phenomenon happens especially when PWS runs at middle PWS rotational speed with part load. The test results demonstrate that the PWS diesel engine performs well with less NOx and soot emissions than the turbocharged diesel engine.