The invention relates to an automatic material turning-over production technology of a packaging box. Pasting of gasket paper and back up paper is carried out on a first paper mounting machine and a second paper mounting machine; the first paper mounting machine and the second paper mounting machine comprise paper board material guide parts, first material guide boards and second material guide boards, wherein the first material guide boards and the second material guide boards are arranged on the two outer sides of clamping parts; the first material guide boards and the second material guide boards are symmetrically arranged; the distance between each material guide board and the corresponding second material guide board is gradually increased from bottom to top, and the distance between the lower ends of each first material guide board and the corresponding second material guide board is consistent with the width of paper boards in the axial direction of a second rotating shaft; a first material pushing conveying belt and a second material pushing conveying belt are horizontally arranged on the inner sides of the lower ends of the first material guide boards and the inner sides of the lower ends of the second material guide boards, and the conveying faces of the first material pushing conveying belt and the second material pushing conveying belt are aligned with the conveying face of a back up paper feeding mechanism of the second paper mounting machine; and the clamping parts are located between the first material pushing conveying belt and the second material pushing conveying belt. According to the production method in the technical scheme, production continuity of the packaging box can be effectively improved, continuous production of the high-grade packaging box can be achieved, the production efficiency is improved, and the production cost is reduced.