An epitaxy structure of a light emitting element includes a gallium nitride substrate, an N-type gallium nitride layer, a quantum well unit, and a P-type gallium nitride layer. The gallium nitride substrate includes a gallium nitride buffer layer, a gallium nitride hexagonal prism, and a gallium nitride hexagonal pyramid. The gallium nitride hexagonal prism extends from the gallium nitride buffer layer along an axis. The gallium nitride hexagonal pyramid extends from the gallium nitride hexagonal prism along the axis and gradually expands to form a hexagonal frustum. The N-type gallium nitride layer is located on the gallium nitride hexagonal pyramid. The quantum well unit includes an indium gallium nitride layer located on the N-type gallium nitride layer and a gallium nitride layer located on the indium gallium nitride layer. The P-type gallium nitride layer is located on the gallium nitride layer.