The invention relates to a curing agent for curing marine poor subsoil, which belongs to the technical field of poor subsoil curing. The curing agent for curing the marine poor subsoil is composed by the components of cement clinker, granulating slag or slag, silica fume, polycarboxylic acid type water-reducer, lime, plaster, anhydrous sodium sulphate, caustic soda, sodium silicate and sodium fluosilicate. The adulteration amount of the poor subsoil curing agent is 5%-12% in application, good curing functions can be realized, and the curing agent for curing the marine poor subsoil can be applied in the poor soil curing of building sites, road embankments, roadbeds and ground base layers. The invention has the advantages that: the components of the curing agent are simple, the compatibility is reasonable, the doping amount is less, and the curing effect is good; and during the application process, the construction period is short, the construction cost is low, the induration bearing capacity is high, the induration compression modulus is strong, and the induration permeable resistance is strong.