Since the Huaihai Economic Zone was established，there are five stages in the evolution of regional cooperation：horizontal combination，depth expansion，image building，core polarization，strategic planning. The field of cooperation is changed from economic construction to social development，while the subject of cooperation is changed from government departments and organizations to enterprises and markets，the level of cooperation is from horizontal connection to in-depth development，and the effect of regional cooperation is constantly expanding and strengthening. The research on regional cooperation in Huaihai economic zone reflects the process of changing from qualitative description to quantitative revelation，from competition to cooperation，from difference to interaction，and from macro scale to micro scale. Based on the perspective of new national development strategy，the trends of regional cooperation research in Huaihai economic zone will be regional spatial integration，regional urban agglomeration integration，regional collaborative development and urban-rural integration.