Multi robot task allocation is a hot issue in the field of robot research.A new emotional model is used to the self-interested robot,which gives a new way to measure self-interested robots individual cooperative willingness in the problem of multi robot task allocation.Emotional cooperation factor is introduced into self-interested robot,it updates based on emotional attenuation and external stimuli.Then a multi-robot pursuit task allocation algorithm is proposed,which is based on emotional cooperation factor.Combined with the two-step auction algorithm recruiting team leaders and team collaborators,then set up pursuit teams,and finally use of certain strategies to complete the pursuit task.In order to verify the effectiveness of this algorithm,some comparing experiments have done with the instantaneous greedy optimal auction algorithm,the results of experiments show the total pursuit time and total team revenue can be optimized by using this algorithm.