In　this　research,　the　investigation　of　applying　PWS　to　a　diesel　engine　was　performed.　In　order　to　improve　the　power　of　the　diesel　engine　with　pressure-wave　supercharger,　the　grey　relational　analysis　which　focused　on　the　experimental　results　of　the　diesel　engine　was　conducted.　The　analysis　results　show　that　the　intake　air　flow　and　the　exhaust　temperature　have　the　most　important　influence　on　the　performance　of　PWS　diesel　engine.　According　to　the　results　of　grey　relational　analysis,　the　intake　and　exhaust　systems　were　medified.　The　volume　of　the　intake　manifold　was　increased　to　allow　more　intake　air　flow.　The　exhaust　manifold　was　redesign　and　wrapped　by　asbestos　with　an　iron　cover　to　preserve　the　high　exhaust　temperature.　The　experimental　results　show　that　after　adopting　these　measures,　both　power　and　torque　of　the　engine　increase,　and　the　NOx　emission　is　reduced　effectively.