The invention discloses a sawtooth-interlocking-structure flattened bamboo high-strength composite laminated board and a manufacturing method thereof. A flattened bamboo veneer is manufactured througha sawtooth interlocking structure, so that the tensile stress generated by flattening among tabasheer tissues can be effectively released. In the tooth pressing process, the compactness of the tabasheer surface is improved to a certain extent, the density of the inner wall of a bamboo is increased, and warping and cracking caused by uneven internal stress and density distribution after the bamboois flattened can be effectively controlled. A composite laminated board basic unit is formed by gluing two flattened bamboos in a sawtooth occlusion mode, in the composite laminated board made of thesawtooth interlocking structure, the gluing area is increased due to the sawtooth structure, and the shear resistance is greatly enhanced. The density distribution of the cross section of the composite laminated board unit is balanced, the strength of the upper surface and the lower surface of the composite laminated board unit is high, and the anti-shearing capacity of the middle part is high, so that the structural design requirements of bending-resistant components are met; and the composite laminated board subjected to sawtooth occlusion treatment can effectively control deformation generated by internal stress of the bamboo, and the stability and the durability of the composite laminated board are greatly improved.