The invention relates to the field of recycling solid waste and hazardous waste by a pyrolysis method, and discloses a device for condensing and recovering pyrolysis gas. The device comprises a pre-separator, a falling film mixed-cold heat exchanger, a first dividing wall-type heat exchanger, a second dividing wall-type heat exchanger, a reheater and a gas cabinet connected in sequence; the bottomof the falling film mixed-cold heat exchanger is connected with a first separator, a first oil tank and a first reboiler; the bottom of the first dividing wall-type heat exchanger is connected with asecond separator and a second oil tank in turn, and the second oil tank is further connected to the first reboiler, the falling film mixed-cold heat exchanger and a second tank respectively; the bottom of the second dividing wall-type heat exchanger is sequentially connected with a third separator, a third oil tank and a third reboiler; the reheater is further connected with the third oil tank; and the device further comprises a third heat exchanger. The device can comprehensively solve the problems of solid particle separation, heat exchange tube wall hanging or tube blocking phenomena, andpoor heat transfer performance on the oil and gas side, and realizes efficient condensation and classification condensation recovery of the pyrolysis gas.