In this paper, the influence on the mechanical characterization of 3D printing polylactic acid (PLA) fiber orientation and carbon fiber for surface reinforcement studied. The nominal Young’s modulus of 3D printing PLA materials with different PLA fiber orientations was measured by tensile test on the Universal Test Machine. Base on the obtained modulus, isotropic and orthotropic PLA honeycomb panel models were built by using FEM software. The vibration mode shapes and natural frequencies of cantilevered PLA honeycomb panel models were evaluated by FEM methods. In addition, the vibration parameters of the cantilevered 3D printed PLA honeycomb panel was measured by time-averaged and real-subtraction electronic speckle pattern interferometry method. The experimental result of the tested panel is well in agreement with that of orthotropic PLA honeycomb panel model predicted by FEM method. The experimental performance shows that the bending stiffness of the 3D printed PLA honeycomb panel reinforced with unidirectional carbon fiber is improved much more than its torsional stiffness.