The invention provides a cadmium-containing waste residue curing agent as well as a preparation method and an application thereof. The cadmium-containing waste residue curing agent is prepared from the following components in percentage by mass: 50%-75% of a cement curing agent, 5%-10% of a stabilizing additive, 10%-20% of an adsorbent and 10%-20% of a stabilizer, wherein the cement curing agent is portland cement; the stabilizing additive is a mixture prepared from gypsum and quick lime at the mass ratio of 1 to 1; the adsorbent is the mixture prepared from kieselguhr and natural zeolite at the mass ratio of 1 to 1; the stabilizer is the mixture prepared from sodium sulphide and sodium bentonite at the mass ratio of 1 to 1; and the components are screened, mixed and stirred evenly to prepare the cadmium-containing waste residue curing agent. A cadmium-containing waste residue is processed with the cadmium-containing waste residue curing agent; and the leaching concentration of cadmium in the cadmium-containing waste residue can be smaller than 0.065mg/kg. According to the cadmium-containing waste residue curing agent, heavy metal pollution of the cadmium-containing waste residue can be effectively avoided; and the method is suitable for large-scale industrial application.