Certain examples relate to methods of continuously cracking waste rubber or plastics and apparatuses related to the same, to produce oil from waste rubber or plastics. Raw materials comprising a catalyst and rubber or plastics may be extruded in order to separate the air or to prevent oxidization. The raw materials are transported into the cracking chamber, and moved from the inlet to the discharge hole. After the cracking process is finished, the products are discharged automatically through the discharge hole. The separation of air and oxygen in the inlet and discharge hole of the cracking chamber can avoid dangers caused by oxygen entering the cracking chamber, and realize industrial production with continuous feedings. The ratio of the oil can be raised from 19% to 45%-48%, and the loss of production equipment reduced. Production costs are reduced, safety measurements improved, and continuous production is realized.