The invention discloses a panel joint structure for a concrete panel rockfill dam and a construction method of the panel joint structure, and belongs to the technical field of hydraulic engineering. The panel joint structure comprises a concrete panel and concrete toe boards, wherein the concrete toe boards are positioned on the lower edge of the concrete panel; the concrete panel is provided with a plurality of joints which are longitudinally distributed along the concrete panel; the joints comprise vertical extrusion joints and vertical tension joints; the vertical extrusion joints are formed in the middle section of the concrete panel; the vertical tension joints are formed in two ends of the concrete panel. The construction method comprises the following steps: determining the length of a compressive zone; determining longitudinal displacement; calculating the widths of the joints; calculating the quantity of the joints; processing the joints. According to the technical scheme, the panel joints on the concrete panel rockfill dam are scientifically and reasonably calculated; due to the allowable sum of elastic deformation widths, the joints between the panels adapt to longitudinal displacement of the dam, so that extrusion between anti-seepage panels of the concrete rockfill dam is avoided, and the effect of effectively avoiding extrusion damage between the panels is achieved.