Laser ablation is a crucial process in many types of laser-matter interactions. Therefore, an accurate simulation of the laser ablation is beneficial to understanding the underlying physics in those interaction dynamics. Laser ablation simulation essentially depends on the numerical solution of heat conduction equations, usually based on finite difference strategy. Common finite difference methods include forward-Euler, backward-Euler and Crank-Nicolson schemes, corresponding to three specific finite-difference weight factors, i.e. 0, 1, and 0.5. This study proposes a new method based on an optimal weight factor, which is not a fixed value but pertinently searched for each specific problem. Taking the temporal evolution of a one-dimensional temperature field as an example, we have demonstrated that utilizing the achieved optimal weight factor can yield significantly higher accuracy than using the routine weight factors. The results in this study have the potential to better understand the heat conduction dynamics and the laser ablation physics, and hence improve the performance of relevant LMI-based techniques in the future.