The invention relates to a sodium-embedded graphite prepared from an aluminum electrolysis waste cathode and an application thereof, and belongs to the technical field of comprehensive utilization ofindustrial solid waste resources. The method comprises the following steps that the aluminum electrolysis waste cathode are crushed and ground and then are mixed with sodium hydroxide, alkali fusion purification is carried out at the temperature of 350-700 DEG C in a current electric field of 50 mA and 2-10 V to prepare the sodium-embedded graphite, the cooled waste cathode powder is subjected toacid leaching impurity separation by a hydrochloric acid and sodium fluoride mixed solution for multiple times and deionized water is used for washing to obtain sodium-embedded graphite powder; and the sodium-embedded graphite is used as a negative electrode material of the sodium-ion battery. The sodium-embedded graphite prepared from the aluminum electrolysis waste cathode and the application thereof has the advantages of being reasonable in process design and simple in process, the impurity separation and the preparation of the sodium-embedded graphite are coordinated and unified, secondarypollution is avoided, and the preparation method is suitable for resource recycling.