In this study, bamboo scrimber composites (BSCs) were prepared using untreated (BSC-C) and saturated-steam heat-treated (BSC-T) oriented bamboo fiber mats and phenol formaldehyde resin via successive mechanical decomposition and molding recombination processes. The heat treatment of the oriented bamboo fiber mats significantly improved the dimensional stability of the resulting BSCs, but degraded their bending performance. Among them, the modulus of rupture and modulus of elasticity of BSC-C were 196.6 MPa and 18.5 GPa, which were 1.35 and 1.19 times higher than those of BSC-T, respectively. The bending strength indexed values of both BSC-C and BSC-T conformed to the structural bamboo scrimber standard LY/T 3194-2020. The dimensional stability of BSC-T was particularly suitable for use in outdoor flooring applications according to the bamboo scrimber flooring standard GB/T 30364-2013. Consequently, the developed BSCs are promising alternatives to conventional engineered bamboo products for various construction and flooring applications.