Abstract: The development of observing near-Earth objects and the defense strategies of a variety of near-Earth asteroids are investigated. By comparing and analyzing the realization principle, key technology and existing problems of the defense strategies, the applicability, feasibility and effectiveness of the various strategies are evaluated. Furthermore, with the analysis and summary of these strategies, combining with the research status of near-Earth asteroid defense strategies in China, an effective strategy is put forward, which combines a variety of strategies to take the relevant effective tactics coping with the potential threat of the asteroids. For example, the kinetic impactor, the Solar collector, the mass driver, or the low thrust propeller are used on one side of the asteroid, and the gravity tractor is used on the other side, that can more effectively deflect the asteroid toward one direction, and gain time for the development of spacecraft and the implementation of defense strategies.