The invention relates to the technical field of polyester fiber preparation, in particular to a recycling device of waste polyester filaments. The recycling device comprises a metal detection unit, acrushing unit, a purifying and separating unit, an extruding unit, a vacuum unit, a melt filtering unit and a pressure increasing unit, wherein the metal detection unit, the crushing unit, the purifying and separating unit, the extruding unit, the vacuum unit, the melt filtering unit and the pressure increasing unit are connected in sequence, and the pressure increasing unit outputs melts to a spinning device. In a recycling method of the waste polyester filaments, the melt directly spinning waste polyester filaments serve as raw materials, and the method comprises the steps of spinning melt preparation and melt spinning. According to the recycling device and method of the waste polyester filaments, the waste filaments obtained during the melt directly spinning production are used as the raw materials to obtain POY products of 270 dtes/48 f and 155 dtex/36 f, wherein the breaking strength of the POY products is higher than or equal to 1.9 cN/dtex, the CV% of the breaking strength is smaller than or equal to 5.0, the breaking elongation is 126+/-5%, the CV% of the breaking elongation is smaller than or equal to 7.0, the CV% of the yarn unevenness is smaller than or equal to 1.6, theoil containing rate is 0.5+/-0.1%, the intrinsic viscosity of the products is 0.560+/-0.005 dL/g before being oiled, and the products obtained by using the method are high-quality polyester fiber products.