Abstract: The way to match the comprex pressure wave supereharger with 493ZQ diesel engine was studied for improving performance of passenger car diesel engine. It was proved that by matching reasonably the inlet and exhaust system to 493ZQ diesel engine, the optimum speed ratio of rotor of the comprex presure wave supercharger to crankshaft of 493ZQ diesel engine, a good result was brought about. Not only the NOxand smoke of 493PWS diesel engine are evidently reduced, but also an excellent acceleration performance is achieved.