It is an important part of building a high-quality cadre team in the new era to effectively motivate civil servants to be brave in reform and innovation and to take responsibility. Based on the resource conservation theory, the study empirically examines the influence mechanism and boundary conditions of public service motivation affecting change-oriented organizational citizen behavior (COOCB), taking 209 civil servants in Fujian Province as samples through a two-stage questionnaire. The results show that public service motivation of civil servants significantly enhances their COOCB. Job crafting, as a resource-building strategy, plays a full mediating role in the above relationship. Transformational leadership plays the role of “resource caravan passageways” and positively moderates the mediating effect of job crafting. Specifically, in the context of high transformational leadership, the mediating effect of public service motivation on COOCB through job crafting is significantly enhanced, while in the context of low transformational leadership, the mediating effect is not significant. The study expands and deepens the relevant literature on the public service motivation and COOCB of civil servants, provides enlightenment for the application of resource conservation theory in the public sector, and also gives important reference value for promoting the scientific management of cadres under the background of the new era.