Objective To construct a urinary retention risk assessment scale for patients after primary hip replacement and test its reliability and validity. Methods The item pool of the scale was formed by combining literature review, semi-structured interview, Delphi expert letter consultation and pre-survey. A total of 27 patients who underwent primary hip replacement in a Class A tertiary specialized hospital in Chongqing from July to August 2021 were subjected with convenience sampling for pre-investigation. Then 114 patients who underwent primary hip replacement from August 2021 to June 2022 were selected for item analysis and reliability and validity test to further verify the stability of the scale structure. Results A risk assessment scale for urinary retention after primary hip replacement was constructed, which included 3 dimensions and 12 items. The content validity index of the scale was 0.800, Cronbach's α coefficient was 0.758, and test-retest reliability was 0.935. The results of receiver operating characteristic (ROC) curve analysis showed that the diagnostic threshold of urinary retention risk assessment scale for patients with primary hip replacement was 17, the AUC was 0.704 (95%CI 0.578~0.830), the sensitivity was 63.6%, and the specificity was 71.8%. The scale grading results were as follows: 17≤ total score