A pot furnace for calcining petroleum coke at low temperature may include a pot, and a cooling water jacket and a flame path below the pot. The flame path may include eight layers. An inlet of a first flame path layer may be in communication with a volatile channel in the front wall, and is provided with a first flame path layer flashboard An eighth flame path layer may be in communication with a communication flue. Flue gas may be discharged out of the furnace body through a main flue. A furnace bottom cooling channel may be provided below the eighth flame path layer.