Bamboo-wood composite cross-laminated timber (BCLT) is a new kind of wood structure material. Studies of the mechanical properties of BCLT have the potential to improve its utilization. Compared with the traditional testing method, this paper designs a fast and effective nondestructive testing method. Three types of composite BCLT plates were designed and made. Multi-point sampling of unit-converted timber was done using a 900-1700 nm NIR spectrometer. Mechanical properties of the unit converted timber were obtained through a four-point bending experiment. The data set consisted of near-infrared spectrum data and mechanical property data. The NIR prediction model was obtained by partial least squares method. The coefficients of determination for the density, MOR and MOE prediction models were 0.88, 0.88, and 0.85, respectively. Finally, the finite element modeling analysis of BCLT plate was carried out according to the element material prediction model, and the prediction of mechanical properties of BCLT plate was achieved. For the three BCLT plates, the prediction error of the finite element model was less than 10%, showing that the finite element analysis method is feasible to predict the mechanical properties of BCLT plate.