This article presents the high-exactitude analysis of hygro-thermo-mechanical vibration of the three-phase multi-scale hybrid composite angle-ply laminated rectangular plate (MHCALRP) for different couples of boundary conditions, within the context of the refined higher-order shear deformation theory with fifteen variables (RHOSDT15). Defining the system's kinematics according to RHOSDT15 is the essential step toward achieving sufficient accuracy in the elucidation of vibrational behavior of the moderately thick plates. The numerical solution is acquired by implementing the generalized differential quadrature method (GDQM). The accuracy of the employed approach is evaluated by comparing the results with the published studies. As a practical conclusion, it is revealed that the orientation angle of the macrofibers can effectively compensate for the lack of nano-reinforcement and the absence of extensional load to overcome the negative impacts of hygro-thermal environment in an affordable cost. The influence of extensional load, nano-/macro-scale reinforcements on the vibrational response of the MHCALRP is completely elucidated. Additionally, a comparative study is performed based on deep neural network (DNN) and its learning parameters are calculated according to adaptive Adam optimization method. Importance of this comparative study is related to providing a non-model-based system by means of a cutting-edge artificial intelligence method to predict vibrational response of the structure.