The invention belongs to the field of machinery, is especially suitable for the field of excavating, and specifically relates to a step-tooth excavating method of reciprocating
impact excavators, and a step-tooth reciprocating
impact excavator used for realizing the step-tooth excavating method. The step-tooth reciprocating
impact excavator comprises a
machine body, a travelling mechanism, an impact blanking mechanism and the like; the impact blanking mechanism is arranged on the
machine body; and the travelling mechanism is arranged on the lower part of the
machine body. The impact blanking mechanism comprises a step-tooth impact-
cutting device, an impact power box, a power impact part, an impact guiding element and the like; step teeth are formed by adjacent impact teeth arranged on the step-tooth impact-
cutting device. The step-tooth impact-
cutting device is driven by the power impact part, material to be excavated is impacted to be step shaped so as to obtain two or more opposite free faces, and
pressure stress and / or structural strength relative to original material is reduced greatly. When the impact teeth is used for excavating for another time, the two or the more opposite free faces are used for reducing
impact resistance greatly; generation of oversized material blocks, which fall because of excavating, is avoided; impaction efficiency is increased, and equipment depreciation is reduced.