The invention discloses a manufacturing method for high-modulus low-shrinkage PET industrial yarn, and the technological process of the method is as follows: hyperviscous melting to polyester fiber raw materials, metering, spinning, cooling, oil applying, stretching, hot shaping and reeled forming, wherein the cooling process sequentially comprises four parts including slow-cooling, pre-cooling, calm zone cooling and blow cooling, and the pre-cooling part adopts a passive hollow ring-shaped belt device. Through the introduction of the pre-cooling device, the irregularity caused by tows quivering produced under the down moving of a solidification point of fiber can be reduced, the deviation ratio of linear density can be controlled within a lower range, the purpose of reducing orientation and crystallization of embryo fiber is achieved, finally high-modulus low-shrinkage PET industrial yarn can be obtained, the high-modulus low-shrinkage PET industrial yarn has the advantages of high modulus, low dry heat shrinkage percentage, low breaking elongation and low linear density deviation ratio, and practical application can be well met.