The invention discloses a method for detecting the content of heavy metal silver ions based on carbon-spot light scattering sensing; the method comprises the steps of adding 2 MuL of prepared carbon-spot stock solution into a centrifugal tube, adding cysteine solution, diluting to 2 mL with BR (Britton-Robison) buffer solution to form a carbon-spot/cysteine light scattering probe, measuring scattering light signal intensity of the probe at 295 nm, and marking as I0; adding another carbon-spot/cysteine light scattering probe into a silver ion solution of different concentration, measuring in the same way as that for I0, calculating linear relationship between a variation in the light scattering signal intensities of the carbon-spot/cysteine light scattering probe with or without added silver ions, and the concentration of the silver ions according to the variation in the scattering light signal intensities; adding sample solution under test according to the method of step II, and calculating the mass or concentration of silver ions in the sample under test. The method of the invention is simple, quick and highly sensitive and can provide accurate results.