The contamination control of silicon wafer surface is more and more strict. Many investigations have been done to inspect defects on silicon wafer. However, rare studies have been reported on defect component inspection, which is also critical to trace the source of defects and monitor manufacturing processes in time. In order to inspect the components of contaminated particles on silicon wafer, especially with a high-speed, in-line mode and negligible damage, a dual nanosecond pulse laser system with both wavelengths at 532 nm is designed, in which one laser pumps the particles away from the wafer surface with negligible damage, the other laser breaks down the particles in the air above the wafer surface to obtain the emission lines of the contaminated particles by a spectroscopy with intensified charge coupled device. The sensitivity of the dual pulse laser system is evaluated. The particle dynamic process after pump is analyzed. The results in this work provide a potential on-line method for the semiconductor industry to trace the sources of defects during the manufacture process.