<p>The integration of positive psychology into second language (L2) education has generated increasing interest in L2 teachers’ perceptions of a supportive work environment (SWE), given its close relationship with their mental health. However, a reliable and concise scale to measure this perception, with strong psychometric properties, has yet to be developed. This study aims to address this gap by developing a streamlined version of the Supportive Work Environment Scale (SWES) and specifying its contributions to emotional experiences, a crucial component of mental health. The study involved two samples, totaling 753 Chinese L2 teachers. In Sample 1 (<i>n</i> = 351), exploratory factor analysis identified a three-factor structure for the SWES, consisting of 20 items across three factors: school support, supervisor support, and colleague support. Confirmatory factor analysis conducted on Sample 2 (<i>n</i> = 402) supported the model’s fit. The SWES also demonstrated good convergent validity, discriminant validity, and internal consistency. Additionally, it showed that enjoyment was most strongly linked to school support, pride to supervisor support, anxiety to colleague support, and anger to school support. These findings suggest that the SWES is an effective tool for assessing L2 teachers’ perceptions of SWE and underscores its role in shaping their emotional experiences.</p>