Abstract: The technology of near earth asteroid rendezvous, orbiting, landing, and sampling return has been highly developed for decades. OSIRIS-REx analyzes the features of C type asteroid and conducts asteroid sampling. Hayabusa-2 aims to sample under the surface of the asteroid. NASA and ESA begins to turn to Planetary Defense. ARM program sets for asteroid capture and orbital redirection, while ESA and NASA put forward a plan of asteroid impact and deflection assessment. Impact test will be arranged on the binary system to accumulate technology. Besides, Planetary Resources Inc. and Deep Space Industries havemade the blueprint for asteroid commercial mining, respectively, and have carried outorbit verification. The process of near Earth Asteroids detection is reviewed, focusing on OSIRIS-Rex, Hayabusa-2, Planetary Defense of NASA and ESA and Strategic planning of commercial mining for asteroid mining companys. Some key technologies of Planetary Defense and mining in the future are summarized.