To translate and cross-culturally adapt the anterior cruciate ligament-return to sport after injury (ACL-RSI) into simplified Chinese [ACL-RSI (Cn)].In this diagnostic study, the translation, cross-culturally adaptation, and validation of the ACL-RSI was performed according to international guidelines. A total of 112 patients with ACL reconstruction participated in this study. All were capable of competitive sports before the injury and completed the Knee Injury and Osteoarthritis Outcome (KOOS), the International Knee Documentation Committee (IKDC), the Tampa Scale of Kinesiophobia (TSK), and the Tegner activity score. Forty-eight patients completed the ACL-RSI (Cn) twice within two weeks. The validity was tested using seven premade hypotheses. Internal consistency, reliability, and measurement error was assessed.At meanly 15.6 months postoperative, 81 (72.3%) patients returned to sport, with 57 (50.9%) to competitive sport and 24 (21.4%) to recreational sport. Thirty-one (27.7%) patients didn't return to any sport, with 19 (17.0%) still had planned to return, and 12 (10.7%) gave up sport. The ACL-RSI (Cn) demonstrated excellent validity with all hypotheses confirmed. The outcome of ACL-RSI (Cn) was strongly correlated the KOOS subscale quality of life (r = 0.66, p<0.001), the TSK (r = -0.678, p<0.001), the Tegner score (r = 0.695, p<0.001). There was statistic difference between cases returned (68.6 ± 10.1) and didn't return to sport (41.3 ± 17.7), p<0.001; between cases returned to competitive (71.1 ± 8.9) and recreational sport (62.9 ± 10.5), (P = 0.002); between cases who planned to return (50.7 ± 14.1) and gave up sport (26.5 ± 11.7), (P<0.001). The internal consistency (Cronbach's α = 0.96) and test-retest reliability [intra-class correlation coefficient (ICC) = 0.90] was excellent. The measurement error, floor and ceiling effect was satisfactory. Administration time was 3.2 minutes, and no item was missed.The ACL-RSI (Cn) scale was confirmed as a valid, reliable, and feasible tool for evaluating psychological factors influencing return to sport.