The invention belongs to the technical field of laser welding, and discloses a method for achieving laser micro-welding. The method comprises the steps that a CW digital modulation mode is set, and the modulation frequency, the light emitting frequency and the duty ratio of a modulation signal are set; digital modulation is carried out on a light emitting signal of a laser device of laser processing equipment according to the modulation signal; and the laser device outputs multiple short pulse square waves within the duration of validity of the light emitting signal of the laser device. According to the method, the light emitting signal of an existing ms-level laser device or continuous laser device is modulated, lasers achieve light emitting in a small and stable square wave multi-pulse form, single-point multi-pulse welding is achieved with small power, and therefore the welding requirements of thin plate materials being 0.1 mm or below and high-reflection materials are met, and the application of the ms-level laser device to the field of micrometer-scale and nanometer-scale precision micro-welding is achieved.