The invention discloses a diversified utilization system and method for petrochemical waste heat in different seasons. The diversified utilization system comprises an absorption-type cold and hot integrated machine, a first absorption-type heat pump, a first heat exchanger, a second heat exchanger, a first hot water pipeline, a first high-temperature material pipeline, a first low-temperature material pipeline, a second high-temperature material pipeline, a second low-temperature material pipeline and a second hot water pipeline; the first hot water pipeline sequentially communicates with an absorber, a condenser, the first heat exchanger, the absorption-type cold and hot integrated machine and the second heat exchanger, wherein the absorber and the condenser are arranged on the first absorption-type heat pump; the first high-temperature material pipeline communicates with a first generator; the first low-temperature material pipeline directly or indirectly transmits heat of low-temperature materials to a first evaporator; the second high-temperature material pipeline communicates with the first heat exchanger; the second low-temperature material pipeline communicates with the second heat exchanger; and the second hot water pipeline communicates with the absorption-type cold and hot integrated machine. The second heat exchanger, the first absorption-type heat pump and the firstheat exchanger transmits the heat to water in the first hot water pipeline, the absorption-type cold and hot integrated machine absorbs the heat of water in the first hot water pipeline and transmitsthe heat to water in the second hot water pipeline.