The microstructure and magnetic properties of Fe-Co-Ni-Al-Ti-Cu hard magnetic high entropy alloys, prepared by the arc-melting technique, were systematically investigated by adjusting the cooling rate. It was found that the coercivity was approximately 20 Oe when homogenized at 1150°C followed by water quenching, whereas it increased to approximately 750 Oe when air-cooled under the same homogenization conditions. Additionally, the saturation magnetization also increased. Transmission electron microscopy (TEM) was used to investigate the effect of cooling rate on the microstructure and chemical composition of Fe-Co-Ni-Al-Ti-Cu high entropy alloys.