Micro-and nano robots are artificial robots with micrometer or nanoscale capabilities that can realize autonomous motion, communication behavior, and intelligent response in complex biological environments. These robots can use a variety of external stimuli, such as magnetic field, light, acoustic waves, temperature, etc., to control the direction and speed of their movement, and to cooperate with other robots or biological cells to achieve the identification and intervention of specific goals in the organism. These robots have the advantages of high efficiency, precision and safety, and can be used in various applications in the biomedical field, such as drug delivery, imaging, diagnosis, treatment and so on. Communication behavior, intelligent response characteristics and biomedical case of micro-and nano-robots: Micro-and nano-robots based on ferrite nanoparticles (FNP) can realize the magnetron movement and communication in the live body. They loaded FNP on different shapes of silicon-based carriers to form different types of micro-and nano-robots, such as disk, rod and spiral type. These robots can control their motion direction and speed through an external magnetic field and communicate with other robots or external devices through FNP MR. These robots were used to achieve various functions in the body, including drug delivery, imaging and treatment in mice. Micro-and nano robots based on DNA origami technology can realize light-controlled motion and intelligent response in the live body. They fold DNA molecules into micro-nano robots with triangular frames, and connect different types of functional molecules at their vertices, such as fluorescent molecules, drug molecules, antibody molecules, etc. These robots can control the direction and speed of their motion through external lasers and achieve intelligent responses with other robots or biological cells through base pairing of DNA molecules. These robots were used to achieve various imaging, diagnostic and therapeutic functions in mice. Micro-nano robots based on metal-organic framework (MOF) can realize sound-controlled motion and intelligent response in living life. MOF molecules were loaded on a silicon-based carrier with hollow structure to form micro-nanorobots with porous properties. These robots can control their motion direction and speed through external ultrasound waves, and achieve an intelligent response to biomolecules through the adsorption properties of MOF molecules. These robots were used to perform drug delivery and treatment in mice.