The invention belongs to the technical field of biological detection, and discloses a method for detecting hydrogen peroxide and related targets based on a nanoprobe. According to the method, a water-soluble rare earth doped CaS: Ce<3+>/Ln<3+> nano material is used as a fluorescent probe, rare earth ion luminescence is quenched through an oxidation-reduction reaction of hydrogen peroxide and cerium ions, and the concentration of hydrogen peroxide is detected by utilizing the change of the fluorescence intensity of doped rare earth ions. The method can be used for detecting hydrogen peroxide ina standard solution or reactants in an enzymatic reaction for generating hydrogen peroxide, can further realize the detection of hydrogen peroxide, biological enzyme or substrate (such as xanthine) in the serum, has the advantages of being simple and convenient to operate, good in anti-interference performance, rapid, sensitive, economical, practical and the like, can provide theoretical basis and technical support for real-time detection of hydrogen peroxide and hydrogen peroxide generation system related substances in a complex system, and has certain clinical application potential.