The invention discloses a high-viscosity sludge drying treatment system and a method thereof. The system comprises a feeding conveyor, a forming machine, a drying machine, a discharging conveyor, a circulating fan, a condenser, a heater and a filter, the input end of the feeding conveyor is provided with a wet sludge inlet, and the other end of the feeding conveyor is provided with a wet sludge outlet; and the wet sludge outlet is communicated with a first feeding hole in the input end of the forming machine. The sludge is formed through the forming machine, formed wet sludge is dried through the spiral mesh belt conveyor in the drying machine, in the drying process, the wet sludge makes full contact with dry hot air flowing in through the air distribution holes in the surface of the air distribution pipe, the contact area of the formed wet sludge is increased after dispersion, the high-viscosity sludge drying device is high in drying speed, high in drying efficiency and high in sludge moisture evaporation speed, and the drying speed and the drying efficiency are increased.