Space debris is a kind of waste that human beings left in the outer space. When the radar found the space debris target, taking the correct association and tracking of the target, or even accessing the monitoring information of the space debris can be the basis for space debris target catalog management. Combining to the distribution characteristics and motion characteristics of space debris, this paper proposed an improved algorithm for multiobjective data association for loworbit space background, on the base of joint probability data association (JPDA) algorithm. The algorithm is designed to reduce possible joint events, and realized the goal of improving the tracking accuracy and reducing the computational complexity. Both thetheoretical analysis and Monte Carlo simulation shows that the algorithm has certain engineering application value, especially in the condition of a larger number of targets.