The invention relates to an omnidirectional interlocking slope protection building block, which comprises a rectangular body and is characterized in that: a pair of upright L-shaped lapping plates of which the notches are back-to-back and face upwards is arranged on the front lateral surface of the rectangular body; a pair of inverted L-shaped lapping plates of which the notches are back-to-back and face downwards is arranged on the back lateral surface of the rectangular body; the two upright L-shaped lapping plates and the two inverted L-shaped lapping plates are symmetrical about the central cross section of the rectangular body; a first groove is formed between vertical lapping sections of the two upright L-shaped lapping plates, and a second groove is formed between vertical lapping sections of the two inverted L-shaped lapping plates; an ecological through hole is formed on the rectangular body; and rope holes are formed on horizontal lapping surfaces of the upright L-shaped lapping plates and horizontal lapping surfaces of the inverted L-shaped lapping plates in the longitudinal direction. Simultaneously, the invention also provides a lapping interlocking method for the omnidirectional interlocking slope protection building block. By the method, an erosion preventing slope protection building block net can be constructed, and the erosion preventing slope protection building block net has high adaptability and erosion resistant capacity, high porosity and water permeability, convenience for construction and low maintenance cost.