绪论明中期在榆林构建之营堡纵深防御体系,与在河套实行之“搜套”攻势防御体系,皆在仁宣以后明朝边疆收缩政策大背景下,在蒙古逐渐由阴山走廊进入河套地区之后,顺应了明朝在北部边疆的战略劣势与防线内徙,从而皆将明朝河套防线定位于榆林一线。在这一军事背景下,营堡纵深防御体系所存在的防御漏洞,与西北巡抚主张保境安民之政治立场,皆从技术与政治两个层面,催生了直接御敌于国门之外的榆林明边墙防御方案。由于这一方案符合节约财政、保障内地之要求,得到了户部、西北巡抚系统的支持;由于搜套军队系统常年搜套无功,为避免承担罪责,亦逐渐转向这一防御方案。虽然兵部出于军事立场,多次反对这一方案,但在宪 Introduction In the middle of Ming Dynasty, Yingbao’s defense system built in Yulin and the “search and rescue” defense system implemented in Hetao were all gradually entered into the Loop from Yinshan Corridor under the backdrop of the Ming Dynasty border collapse policy after Ren Xuan. After the region, conform to the Ming Dynasty in the northern border strategic disadvantage and internal defense, which will be located Ming Dynasty Hetao line Yulin line. Under this military background, the defensive loopholes in the defense system of Yingbao and the political standpoints advocated by the governors of the Northwest to protect the peace and safety are both inspired by the technical and political levels of Yulin Ming Side wall defense program. Since this program meets the requirements of saving the financial resources and guaranteeing the Mainland, it has been supported by the Ministry of the Interior and the Northwest Governor System. In order to avoid being guilty of crimes, the search and defense military system has gradually shifted to this defense program. Although the military department out of military position, repeatedly opposed this program, but in the constitution