The invention discloses a laser shock pressure welding automatic clamping and part fetching device and a method thereof and relates to the field of high-speed shock welding. The laser shock pressure welding automatic clamping and part fetching device comprises a laser generator, a welding device, a three-coordinate mobile platform device and a control device. A laser transmitter comprises a pulselaser, a reflector, a focus lens, a focus lens support and a focus lens support position regulation device. A control system comprises a laser controller, a computer, a three-dimensional mobile platform controller and a position sensor. A welding clamping device comprises a clamping device composed of a restraint layer, an absorption layer, an impact plate, a restraint layer support, a restraint layer support position regulation device, a base plate, a rotary rod, a connecting rod and a pressing block. A pulse laser is adopted as an energy source, and solid-state welding of a metal plate and aplate is achieved. According to the automatic clamping device, through a link mechanism and a wedge mechanism, the pressing block loosens automatically during part fetching, the pressing block achieves automatic clamping during welding, the automation degree is high, and convenience and quickness are achieved.