NOVELTY - Greenhouse-heat collector type solar system for drying sludge comprises a charge bin (11), a solar greenhouse (2), a solar air heat collector (1), a pipeline fan (3) and a piece of ventilation equipment. The solar system further comprises a three-way tube, where the first end of the three-way tube is communicated with the outside atmosphere via a first valve (14), the second end is communicated with the solar greenhouse via a second valve, and the third end is communicated with the hot air inlet of the solar air heat collector, which is communicated with that of the solar greenhouse.    USE - The solar system is useful for drying sludge.    ADVANTAGE - The system: has low operation cost, zero emission, realizes industrialized and automatic operation, and actively utilizes and reduces sludge.    DETAILED DESCRIPTION - Greenhouse-heat collector type solar system for drying sludge comprises a charge bin (11), a solar greenhouse (2), a solar air heat collector (1), a pipeline fan (3) and a piece of ventilation equipment. The solar system for drying sludge further comprises a three-way tube, where the first end of the three-way tube is communicated with the outside atmosphere via a first valve (14), the second end is communicated with the solar greenhouse via a second valve, and the third end is communicated with the hot air inlet of the solar air heat collector. The hot air outlet of the solar air heat collector is communicated with the hot air inlet of the solar greenhouse. A heat storage layer is paved on the bottom surface of the solar greenhouse, and a spreader and a piece of sludge turnover equipment are further installed in the solar greenhouse. An INDEPENDENT CLAIM is also included for drying sludge utilizing the greenhouse-heat collector type solar system, comprising: (i) conveying the sludge to the solar greenhouse via the feeding bin, where the spreader uniformly spreads the sludge on the floor in the solar greenhouse to dry the sludge and the sludge turnover equipment turns over the sludge every 2-5 hours, and using the ventilation equipment for forcibly ventilating and drying; (ii) passing the dried sludge through the following working conditions: the solar air heat collector supplies heat to the solar greenhouse and the solar greenhouse directly absorbs the solar energy from 8-9 a.m. to 5-6 p.m., the heat storage layer supplies heat to the drying chamber until the temperature of the heat storage layer is reduced to room temperature from 5-6 p.m. to 6-9 p.m., and airing the dried sludge is aired via the ventilation equipment in the night and rainy days; (iii) performing ventilation process, which passes through the following working conditions: in the initial stage of the sludge drying, water evaporation rate is high, the humidity in the solar greenhouse is high, the first valve is opened, and the ventilation equipment in the solar greenhouse operates, in the post stage of the drying and the water evaporation rate is low, opening the first valve and the second valve to flow back a part of hot air to reduce the exhaust and heat dissipation loss, and adjusting the first valve and the second valve according to the temperature and humidity in the solar greenhouse to control the intake amount and exhaust amount.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of the solar system.    Solar air heat collector (1)    Solar greenhouse (2)    Pipeline fan (3)    Charge bin (11)    First valve (14)