To improve the track association with sensor bias between networking radars a novel gray track correlation algorithm based on topology sequence method is proposed. Firstly the gray theory is utilized to get the gray correlation matrix of topology sequence and the correlation measurement between tracks is set up. Then the correlation measurement matrix is processed by global optimization method to get the association couples. The algorithm makes use of global optimization to avoid the influence on correct probability owing to the improper choice of threshold and utilizes space distribution and status messages of the tracks effectively. The simulation results show that the track correlation with sensor bias can be achieved more effectively.