Abstract: The waste clay has poor engineering properties and is difficult to be used as subgrade material for resource utilization. This paper studies the effects of different amounts of ground granulated blast furnace slag-desulfurization gypsum-calcium carbide slag(GDC)soil stabilizer on the mechanical properties and micro mechanism of marine clay. Firstly,the unconfined compressive strength,splitting tensile strength and water stability tests were used to evaluate the macroscopic mechanical properties of GDC solidified soil. Then the interaction mechanism between the curing agent and marine clay was analyzed by SEM and XRD,and compared with the traditional cement curing scheme with the same content. The results show that the unconfined compressive strength of GDC solidified clay and cement solidified clay increases with the increase of curing agent content and curing age. Compared with cement solidified soil,GDC solidified soil has better water stability. With the growth of curing age,GDC solidified soil shows higher compressive strength,splitting resistance and lower brittleness;SEM and XRD analysis shows that GDC solidified soil would continuously generate cementitious hydrates such as hydrated calcium silicate(C-S-H),hydrated calcium aluminate(C-A-H) and expansive hydrated product ettringite(Aft) during curing,which can effectively wrap and connect clay particles and fill soil micro pores. Compared with cement stabilized soil,GDC solidified soil at the age of 28 days has a denser microstructure and a wider coverage of hydrated products. GDC soil stabilizer has remarkable effect on the modification of waste marine clay and has a good application prospect.