The invention relates to a double-channel long material continuous casting and continuous rolling production line and a production method of the production line. The production line comprises a continuous casting machine, a quick insulation roller way, a heat feeding and heat loading transportation system, a heating furnace, a furnace area roller way, a furnace rear roller way and a steel rolling unit; the continuous casting machine, the quick insulation roller way, the furnace rear roller way and the steel rolling unit are joined in the operating direction of a casting blank in sequence to form a short-flow production channel; the continuous casting machine, the heat feeding and heat loading transportation system, the heating furnace, the furnace area roller way, the furnace rear roller way and the steel rolling unit are joined in the operating direction of the casting blank in sequence to form a long-flow production channel; and a casting blank flowing direction control mechanism is arranged on a blank outlet roller way. The double-channel long material continuous casting and continuous rolling production line has short-flow and long-flow production channels, can quickly switch two production modes, is flexible in production, is wide in product coverage, is high in market adaptability, and is low in production cost; and the two production channels are mutually complemented and are flexibly switched, equipment is simple, implementation is easy, and comprehensive investment is low.