The present disclosure relates to flake graphite cast iron having high workability and a preparation method thereof, and more particularly, to flake graphite cast iron with a uniform graphite shape, low chill formability, a high strength such as a tensile strength of 350 MPa or more, and excellent workability and fluidity by controlling each of the contents of manganese (Mn) and sulfur (S) and carbon (C) and silicon (Si) included in the cast iron and a carbon equivalent (CE) to predetermined ratios, and a preparation method thereof.