The welding quality is strongly affected by laser pulse frequency and scanning mode in laser soldering. Laser soldering was experimented on copper clad laminate with Sn-Ag-Cu lead-free solder with 100% 12 W power SP-12P fiber pulse laser soldering system, and laser soldering experiment was carried out with different pulse frequency and scanning mode. The results show that cavitations occur and oxide film is crushed on the interface between solder and bonding pad under linear scanning mode by 500 kHz laser. The solder is wet and spreads on the bonding pad, and then laser soldering comes true on the copper clad laminate with Sn-Ag-Cu lead-free solder by pulse laser scanning.