The invention discloses a magnetic/pH dual-response micro-nano robot for tumor diagnosis, and relates to a preparation method and a detection application method of a magnetic/pH dual-response and quantum sensing micro-nano robot MNR (Fe3O4 (at) PDA-FNDs (at) CaP). Aiming at the problems that an existing micro-nano robot is low in targeting efficiency and lacks dynamic feedback in the treatment process, the technology provides a diagnosis and treatment integrated strategy of active targeting therapy-quantum instant detection. According to the micro-nano robot, magnetic Fe3O4 is used as a core, and an incomplete coating PDA middle layer, an FNDs quantum sensing layer, a glucose oxidase trigger layer and a pH response CaP shell are sequentially constructed. The incompletely coated PDA layer is a key structure for inducing ferroptosis treatment, and the CaP shell is decomposed in a targeted environment to realize controlled release of functional components and trigger a cascade reaction, so that the ferroptosis treatment efficiency is enhanced. Meanwhile, by utilizing the change of the relaxation time of the FNDs, the generation concentration of. OH in the ferroptosis process is detected, and the treatment effect is monitored in real time.