The invention discloses a casting technology of an engine cylinder cover and a core assembling structure, and relates to a casting technology. A sand mold is manufactured through the cold core box core manufacturing technology, an intra-cavity inner sand core is manufactured through the precoated sand hot core box core manufacturing technology, vertical casting is carried out after the appearance is locked through sand core discharging, and a good solution is provided for cylinder cover air holes, sand holes, leakage, inner cavities and surface smoothness. By means of implementation of the technology, the casting yield is increased to be more than 98%.