In order to study the F3 system, an accurate global adiabatic potential energy surface is reduced in the present work. The high level ab initio (MCSCF/MRCI level) methods with big basis set aVQZ are used to calculate 27690 potential energy points in MOLPRO quantum chemistry package using Jacobi coordinate. Meanwhile, B-spline fit method is used to reduce the global potential energy surface in this present work. The shallow well complexes are found in the present work when the angles θ = 30°, 60°, and 90°. Analysing the global potential energy surfaces one can get the conclusion that reactants should overcome at least 0.894 eV energy to cross transition state and reach products.