Objective To construct an assessment form for the release of protective restraints in department of psychiatric medicine, and to provide guarantee for patient safety. Methods Based on literature review and expert interviews, and based on the theoretical model of planned behavior, the Delphi method was used to conduct 2 rounds of expert consultation involving 20 nursing experts from 13 provinces and municipalities to establish an assessment form for the release of protective restraints in department of psychiatric medicine. Then another 6 experts were invited to assess the content validity index (CVI) of the assessment form. Results The expert response rate stood at 100% in both rounds. The authority coefficients were 0.908 and 0.950, and the Kendall coordination coefficients were 0.157 and 0.238, respectively (all P<0.05). Finally, the assessment form for the release of protective restraints in department of psychiatric medicine had five first-level indicators (emotions, behavior, degree of cooperation, knowledge of restraint related health education, and awareness) and 20 second-level indicators. S-CVI of the form was 0.962. Conclusion The preliminarily established assessment form for the release of protective restraints is scientific and reliable. It can be used as a tool for the removal of protective restraints, making usage of protective restraints in clinical settings more standardized.