Abstract: With the development of modern science and technology, especially space technology, present situation of security cooperation has been becoming more and more dangerous in outer space. It is shown that the threat of individual countries to seek absolute advantage and absolute hegemony in outer space be further intensified, the tendency of weaponization and arms race be more obvious,effect of self-destruction of space debris be more serious and man-made pollution be worsen in outer space environment. The main reasons that lead to sluggish of space security cooperation include as the following, imbalance of the distribution structure of powers in space security cooperation, insufficient of coercive force to restraint space weaponization and arms race, weakness in the basis of common interests of governance on space debris, lack common awareness of security of space environment. Therefore, to advance space security cooperation, we should look for a solution to security cooperation through coordination of international security interaction, severely restraint space weaponization and arms race, promote the formulation of the rules for space and enhance security cooperation of space environment through initiative of new security concept.