Vector solitons play important roles in modern communication and nonlinear optics. Mode-locked fiber laser provides an important platform for investigation of vector solitons. Processing of vector soliton in a carbon nanotube mode-locked erbium fiber laser is reviewed. Various types of polarization processing trajectories have been identified. The experiment results show the presence of polarization processing of vector soliton which is as a nonlinear attractor, and indicate the possibility of a new type of mode-locked fiber laser. The application and development of the new type of mode-locked fiber laser are prospected.