Abstarct: In this dissertation, The developed precondition method called the power preconditioning method has been used to analyze and study steady and unsteady laminar flows with a fixed attack angle passing through the hydrofoils in three dimensions. Researchers pay special attention to steady and unsteady flows in various fields. Flow with low Reynolds number is studied by researchers due to special applications such as drones and robots on a very small scale. Also, many experimental and numerical researches have been done on the dynamics of vortices, the study of hydrofoils and etc. In this study, the Navier-Stokes three-dimensional equations are modified by changing the temporal derivative quantity of the governing equations. Using the velocity field and the power relation, the preconditional matrix was modified and the Jameson finite volume numerical method of cell-center was used to integrate the governing equations. Unsteady flow is solved with help of the dual-time algorithm, time integration is done with the help of the explicit four-step Range-Kota time integration method. The simultaneous equations of the problem, which includes the equations of continuity and momentum in the Cartesian coordinate system in three dimensions, has been solved using an algorithm in C++ software. Steady and Unsteady three-dimensional incompressible flow passing through NACA 0012 hydrofoil is solved with Reynolds numbers and different attack angles. The results are in a good agreement with other studies of researchers and it can be seen from the results that the power preconditioning method has a high convergence rate and computations time reduces by 20 to 50 percent compared to other methods .