The invention discloses a production process and device of an expanded polytetrafluoroethylene board. According to the technical scheme, the production process is characterized by comprising the following steps: screening refrigerated polytetrafluoroethylene dispersion resin, adding additives according to a ratio, ripening the mixed raw materials to obtain a blank, extruding the blank to form a rod material, rolling the rod material through a two-roller shaft to form a flaky film, degreasing, drying and stretching the flaky film, longitudinal and transversely drawing the flaky film, laminating the flaky film which is drawn in two directions, pressing the flaky film to obtain a sheet, and finally trimming the sheet to obtain the board. The production process of the expanded polytetrafluoroethylene board breaks through a traditional board production process, the problems of creeping and cold flow of an ordinary board can be solved, the compression resistance, the creeping loosening rate, the compression rate, the resilience property and the like of the expanded polytetrafluoroethylene board are obviously improved, and the expanded polytetrafluoroethylene board can be widely used for sealing aerospace, medical, food and petroleum pipelines and the like and has extremely good application temperature, an anti-aging property, no toxicity, no pollution and the like.