Objective To develop a self-rating scale of shared decision-making (SDM) competence in nursing staff and test its reliability and validity, and to provide an assessment for measuring nurses′ SDM competence. Methods Semi-structured interview and Delphi technique were utilized to develop the self-rating scale, then 1,247 nurses completed the scale to test the reliability and validity. Results The final version of the self-rating scale included 3 subscales, namely knowledge and experience, skills and abilities, and comprehensive quality, totaling 51 items. The overall Cronbach′s alpha coefficient was 0.984, and the average scale-level content validity index （S-CVI/ave） was 0.974. Exploratory factor analysis identified 2 common factors in the knowledge and experience subscale, 4 common factors in the skills and abilities subscale, and 2 common factors in the comprehensive quality subscale, which accounted for 78.272%, 75.975% and 87.208% of the total variance, respectively. Conclusion The self-rating scale is reliable and valid for measuring SDM competence of nurses.