With  the Pulsed Laser Single Event Effects facility(PLSEEF), the backside  testing of High-performance CPU device based on 90nm SOI-CMOS technology  has been done. The abundant SEE phenomena and its effects on the  computer performance were observed by the laser scanning. The backside  radiation technology can test the internal SEE sensitivity volumes in  device directly by avoiding the mental layers from the front side. It’s  proved that the pulsed laser was a powerful tool for SEE sensitivity  assessment of the devices used in Satellites, and also a tool for the verification of the SEE mitigation techniques.