self-assurance       
noun [ U ]  approving uk/ˌself.əˈʃɔː.rəns/ us/ˌself.əˈʃʊr.əns/
C2 自信
confidence that you have in your own abilities
  She’s an extrovert who exudes self-assurance.  她是一个外向的人,散发着自信的光芒。 
 See: self-assured
 - More examples
 - With all the self-assurance of youth, he felt he would just take a break, then start another band.
 - When the 45-year-old stepped to the microphone, he exuded self-assurance.
 - Given the strength and self-assurance of Pearce's work, it's hard to imagine anyone delivering a more effective, or affecting, performance.
 - To believe more in the applause than in the polls, that is a sign of self-assurance.
 - Self-assurance does not guarantee wisdom.