Teachers' psycho-affective states are considerably reported to play a vital role in English as a foreign language (EFL) education. However, the overall mechanism, realization, and representation of teachers' psychological ill-being (PIB) have been widely kept under the shadow of well-being. To fill this gap, this qualitative investigation examined 46 Chinese EFL teachers' perceptions about the causes, outcomes and solutions of PIB. The results of thematic analysis revealed that PIB was caused by different personal, interpersonal, professional, task, student and contextual factors among Chinese EFL teachers. More specifically, ill-being emerged out of "heavy workload pressure", "mental and physical exhaustion", "unrelated tasks to teaching", "students' classroom behavior and performance", "unfriendly school climate", "poor interpersonal relationships with colleagues" and "social and cultural environment". The findings also indicated that teachers' ill-being led to different outcomes such as "reducing teaching quality", "creating negative emotions", "causing physical and mental health problems", "leading to burnout" and "hurting students' feeling and learning rate". To solve this aversive state, the participants suggested different techniques such as "reducing workload", "learning emotion regulation strategies", "establishing a positive classroom/school climate", "offering teacher training courses", "providing support and facilities for teachers", "increasing salary" and "reading books". A discussion of the findings and implications for EFL teachers, teacher educators and policy-makers is provided to enhance their emotional literacy and competency regarding negative teacher-related emotions in L2 teaching.