Provided is a monofilament and multifilament double-strand sewing thread with tensile expansion performance. The monofilament and multifilament double-strand sewing thread includes multifilaments andelastic monofilaments which are mutually entangled, the multifilaments and the elastic monofilaments are mutually entangled in a juxtaposed structure, the multifilaments are made of FDY filaments, themultifilaments and the elastic monofilaments are of wavy structures, the diameter of the multifilaments is 75%-125% of the diameter of the elastic monofilaments, the strength of the multifilaments isgreater than that of the elastic monofilaments, the flexibility of the multifilaments is smaller than that of the elastic monofilaments, and the poisson ratio of the monofilament and multifilament double-strand sewing thread is smaller than 0 and greater than or equal to 0.5. The monofilament and multifilament double-strand sewing thread has tensile expansion performance and can be actually produced and mass-produced, stitched products are not easy to slip, there is no hairiness to facilitate needling and sewing, the strength is high, and the monofilament and multifilament double-strand sewing thread is suitable for high-speed sewing.