A method and a device for increasing a laser induced shock wave pressure. According to the method, plasmas (21) are generated by impinging an aluminium foil (20) using lasers; a high-voltage pulse electrode (22) discharges to the plasmas (21) to induce and form a photoelectric combined energy field and then high-temperature plasmas (21) having the characteristics of an ultra-high density and an ultra-high speed expansion are induced and generated; a surface to be processed is impacted by the high-temperature plasmas (21) in a restrained state; the laser induced shock wave pressure is increased substantially; the surface of a high-strength material is reinforced, and the strength, hardness, abrasion resistance and anti-fatigue performances of the high-strength material are improved. The device comprises a laser, the electrode (22), a high-voltage power supply (4), a discharging medium (12), a moving platform, etc.