A cooling device of a heating element for an immersion type liquid cooling server, and a manufacturing method for the cooling device. The cooling device comprises: a metal substrate provided on the heating element and covering same. The metal substrate is adjacent to the surface of the heating element. The surface of the metal substrate distant to the heating element comprises a porous metal covering layer located above the heating element and covering same. The porous metal covering layer is exposed on the surface of the metal substrate remote from the heating element and has a thickness of less than 3 mm. By providing a metal substrate having a porous metal covering layer on the surface of a heating element, vaporization cores are improved, the boiling performance of the heating element is improved, and an efficient heat-dissipating effect on the surface of the heating element is achieved.