Background: Undiagnosed COPD is a major problem in China but the optimal screening strategy to identify new cases is unclear. Methods: Cross-sectional study in eight community health centres in four municipalities. Participants completed six index tests (screening questionnaires [CDQ, CAPTURE, Chinese Symptom-based questionnaire, COPD-SQ], microspirometry [COPD-6], peak flow [USPE]) and the reference test (ndd Easy On-PC spirometer). Cases were defined as those with FEV1/FVC below the lower limit of normal (LLN-GLI) on the reference test. Performance of individual screening tests and strategies was evaluated, with cost-effectiveness analyses providing cost per additional true case detected. Findings: 2445 participants (mean age 59.8 [SD 9.6] years, 39.1% [n=956] male) completed the study (February-December 2019), 68.9% (n=1684) were never-smokers and 3.6% (n=88) had an existing COPD diagnosis. 13.7% (n=333) of participants had spirometry-confirmed airflow obstruction. Airflow measurement devices (sensitivities 64.9% and 67.3%, specificities 89.7% and 82.6% for microspirometry and peak flow respectively) generally performed better than questionnaires, the most accurate of which was the Chinese symptom-based questionnaire (sensitivity 63.1% [95% CI 57.6%, 68.3%], specificity 74.2% [95% CI 72.3%, 76.1%]). The combination of Chinese Symptom-based questionnaire and microspirometry used in parallel maximised sensitivity (81.4%) and had specificity of 68%, with an incremental cost-effectiveness ratio of £64.20 (CNY385) per additional case detected compared with peak flow. Interpretation: Simple screening strategies to identify undiagnosed COPD within the primary care setting in China are possible, and a combination of the Chinese symptom-based questionnaire and microspirometry is the most sensitive. Further work is required to explore optimal cut-points. Trial Registration: The protocol for this study was previously published and registered on ISRCTN registry. The number was ISRCTN13357135 and the full study protocol can be accessed at http://www.isrctn.com (ISRCTN13357135). Funding Statement: This research was funded by the National Institute for Health Research (NIHR) NIHR global group on global COPD in primary care, University of Birmingham, (project reference: 16/137/95) using UK aid from the UK Government to support global health research. This paper presents independent research supported by the NIHR Birmingham Biomedical Research Centre at the University Hospitals Birmingham NHS Foundation Trust and the University of Birmingham. Declaration of Interests: The authors declare no conflicts of interest. Ethics Approval Statement: The study has been approved by Peking University First Hospital (2018-R-141, PUFH) and University of Birmingham (ERN_18-1177, UoB).