The main goals of the present study were to investigate the effects of outcome valence on attentional bias toward feedback and examine the internal mechanism of self-defense. We systematically manipulated the outcome valence by providing a bogus score in a rational thinking task and recorded the time positive feedback and negative feedback was viewed in experiment 1. We added the intervention of self-affirmation to examine the self-defense mechanism in experiment 2. The results suggest that (1) in good outcome situations, the participants viewed negative feedback longer than positive feedback. There was a tendency to slightly reduce the attention given to negative feedback in bad outcome situations. (2) Self-affirming participants in bad outcome situations increased their viewing time of negative feedback, which supported the activation of defensiveness.