In order to investigate the feasibility of applying solidified shield muck in road construction, the shield muck from Nanjing Metro was taken as the research object, and the green polymer composite curing agent developed independently was used to solidify the shield muck. The impact of the curing agent dosage and maintenance age on the road performance indicators of the shield muck was analysed using various tests-unconfined compressive strength, direct shear test, California bearing ratio (CBR), resilient modules, and freeze-thaw cycle test. In addition, the micro-characteristics and solidification mechanism of the solidified soil were investigated by scanning electron microscope and X-ray diffraction. The results indicate that the composite curing agent can effectively improve the strength of solidified muck, and with the increase of curing agent dosage and maintenance age, the strength of solidified muck also increases. The CBR and resilient modulus of solidified shield muck substantially improve as the dosage of the curing agent elevates, and the solidified soil can well meet the requirements of the Specifications for Design of Highway Subgrades (JTG D30—2015) and Specifications for Design of Highway Asphalt Pavement (JTG D50—2017). The freeze-thaw resistance of shield muck is poor, while it can be effectively improved after curing treatment. The strength loss and mass loss of solidified soil are less than 20% and 1% respectively. The anti-freezing performance indicators meet the requirements of the specification. After the curing agent has been added to the soil body, the polymer components will absorb water and dissolve, creating a static chelating effect with the mineral ions in the soil, initially reducing the water content of soil and promoting the agglomeration between the soil particles. Meanwhile, the other components of the curing agent generate hydration reaction to form hydrated calcium silicate gel, ettringite and other substances to fill the internal pores of soil, making the soil structure denser and greatly improving the strength.