Appts. for energy recovering through wastes classification and calcination, comprises: a) a crusher (1), crushing wastes (10) into broken species, and sorting the broken wastes based on their specific gravities into mixed wastes, organic waste and light weight wastes, the mixed wastes being disposed by landfill b) a calcination furnace (2a), calcinating the organic wastes and light weight wastes, comprising: - a cracking furnace (3), provided at appropriate place inside the calcination furnace, equipped with a lid at top, for introducing the light weight wastes, a heavy oil line for introducing heavy oil to mix and crack the plastics wastes, an oil gas line for recovering oil gas generated from cracking of the melted plastics in the light weight wastes - a burning plate (2b), provided at a proper place below cracking furnace, equipped with an air line, a gas line and a waste conveying line, whereby organic wastes being spread on the burning plate via the waste conveying line and mixed with air and gas charged from the air line and gas line, the organic wastes on the burning plate being subject to calcinating treatment such that high temperature heat generated from being able to transfer indirectly to the cracking furnace above for melting and a vaporising the plastics into oil gas which is discharged via the oil gas line c) a reactor, receiving and heating the oil gas under controlled pressure to cleave molecules as an irreversible reaction d) a cooler, stepwise cooling the products obtained into the reactor to near ambient temperature to condense the products e) a settling tank, settling down the condensed products obtained from reactor f) an oil/gas separating tank (4), separating the products into a crude oil and a fuel gas g) a fractionating column (6), heating the crude oil h) a cooler (412), cooling the crude oil i) a distiller (7), stepwise distilling the crude oil and collecting and storing respective distillates j) washing tanks, pickling, neutralising and removing contaminants in the distillates to obtain pure diesel and gasoline, whereas fuel gas can be pressured liquified to be stored or packed in cylinders for marketing or used as heat sources for the appts.    USE -   Recovering high added-value converted products such as fuel oil, carbon ash, gases and refractory materials through classifying wastes into combustible wastes and plastics wastes and calcinating.    ADVANTAGE -   The invention can convert useless wastes into high added-value products to achieve the goal of energy recovery.