Preparation method of crystal nylon fiber blended yarn

The invention relates to a preparation method of a crystal nylon fiber blended yarn. The preparation method comprises the following steps: weighing the following raw materials according to the mass percent of the fibers under the common moisture regain: 50%-70% of crystal nylon fibers and 30%-50% of acrylic fibers; then pretreating the acrylic fiber to obtain a raw material 1; the raw material 1 and acrylic fibers are mixed in a sample cotton blending mode, a mixture is obtained, then the mixture is grabbed through a disc bale plucker, opened through a mixing opener and carded into strips through a carding machine in sequence, and a raw material 2 is obtained; drawing the raw material 2 to obtain a raw material 3; roving the raw material 3 to obtain a raw material 4; spinning the raw material 4 to obtain a raw material 5; spooling the raw material 5 to obtain a raw material 6; after the raw material 6 is subjected to doubling and two-for-one twisting treatment, the aramid fiber blended yarn is obtained, the p