Objective To develop Pregnant Women Weight Self-Management Scale and test its reliability and validity.Methods Based on the concepts and theories of self-management,the first draft of the scale was formed through literature analysis,semi-structured interviews,2 rounds of Delphi expert correspondence and pre-surveys.The scale was used to test the reliability and validity of the scale by facilitating the selection of 300 pregnant women who gave birth in April 18-23 2023 at a maternal and child healthcare hospital in Ningxia Hui Autonomous Region.Results The Pregnant Women Weight Self-Management Scale consisted of 8 dimensions and 38 entries with a cumulative variance contribution of 68.560％.The Cronbach's alpha coefficient for the total scale was 0.944,and each dimension ranged from 0.772 to 0.929.The split-half reliability for the total was 0.858,and each dimension ranged from 0.715 to 0.902.The content validity index at the level of the total scale was 0.921,and at the level of each entry was from 0.833 to 1.000.There was a positive correlation between the dimensions and with the total scale score(r=0.178～0.854,P＜0.001).Conclusion The scale has good reliability and validity,and it can be used as a tool to evaluate the self-management ability of pregnant women.