Assisting pre-service teachers in developing readiness for interdisciplinary teaching has been recognized as a crucial direction in teacher education in China. However, there is currently a lack of reliable instrument to measure the readiness. We developed and validated an Interdisciplinary Teaching Readiness Scale (ITRS) for pre-service teachers to fill the gap. We utilized literature review and interdisciplinary teaching competence framework to develop the initial item pool for the ITRS. Data were collected from 234 pre-service teachers at S Normal University (Sample A) for item analysis and exploratory factor analysis (EFA), followed by data collection from 543 pre-service teachers in China (Sample B) for confirmatory factor analysis(CFA), convergent validity, discriminant validity, and reliability testing. Item analysis on Sample A data using the critical ratio method revealed discriminative items, indicating no need for item deletion. PCA showed that the ITRS has a three-factor structure, explaining 77.282% of the total variance. CFA on Sample B demonstrated a good model fit (GMIN/DF = 4.189, RMSEA = 0.077, GFI = 0.852, AGFI = 0.821, NFI = 0.939, RFI = 0.932, CFI = 0.953, IFI = 0.953). Analysis of the AVE for each dimension indicated good convergent and discriminant validity. Reliability testing revealed a high overall Cronbach's α coefficient of 0.972 for the ITRS, indicating good internal consistency. Ultimately, we confirmed that the ITRS consists of three factors(including interdisciplinary teaching knowledge structure readiness, interdisciplinary teaching skills readiness, interdisciplinary teaching attitudes readiness) and 24 items. In conclusion, the ITRS that has been developed shows great potential for promoting the professional development of pre-service teachers, evaluating the effectiveness of teacher education programs, and supporting the development of educational policy. The extensive utilization of this instrument will help to comprehensively assess the overall level of pre-service teachers' readiness for interdisciplinary teaching and to promote the professional growth of pre-service teachers in China. Furthermore, the ITRS, through the implementation of culturally adaptable modifications, can offers invaluable instrumental support and insightful guidance to pre-service teacher education programs globally.