The invention discloses a cleaning method of clogging materials on an RH lower groove and an alloy feed opening. In 20 min and within 20 min after RH production is ended, under the condition that thegroove temperature is higher than 1300 DEG C, an oxygen lance is adopted to blow oxygen to the lower groove; oxygen blowing is performed at three stages, namely the high stage, the middle stage and the low stage according to the distance between the muzzle of the oxygen lance and the bottom of the groove; the distance between the muzzle of the oxygen lance and the bottom of the groove at the highstage is larger than 5.5 m and smaller than 7.0 m, the distance between the muzzle of the oxygen lance and the bottom of the groove at the middle stage is larger than 5.0 m and smaller than 5.5 m, andthe distance between the muzzle of the oxygen lance and the bottom of the groove at the low stage is larger than 4.5 m and smaller than 5. 0 m; and the oxygen blowing speed is 1200-1500 Nm<3>/h. Theclogging materials on the lower groove and the alloy feed opening are melted by heat released by a chemical reaction between sufficient oxygen and Fe left on the inner wall of the groove and the alloyfeed opening; and by using the heat released by a Fe-O chemical reaction and combination with Gibbs free energy characteristics of FeO, Fe3O4 and Fe2O3, the clogging materials on the lower groove andthe alloy feed opening are melted, the refractory material damage is reduced, the condition that the alloy feed opening is blocked by the clogging materials is avoided, the production interruption caused by blockage of the clogging materials is avoided, and the service life of a refractory material in a vacuum tank is prolonged.