Through numerical simulations, this study systematically investigates the physical characteristics of a onedimensional infinite square potential well incorporating finite potential barriers, with a particular focus on the manifestation of quantum tunneling phenomena. By employing the Projected Greens Function (PGF) method, the work explores how structural parameters—such as barrier width, barrier height, and well width—affect the tunneling lifetime of particles. The numerical solution approach has been further optimized to enhance both computational accuracy and efficiency. The analysis of tunneling time provides theoretical guidance for the design and fabrication of semiconductor devices and contributes to a more profound understanding of material behaviors in quantumscale systems. Overall, the results not only offer theoretical support for relevant experimental research, but also propose new perspectives for extending the application of the PGF method to higherdimensional and more complex potential problems.