The invention belongs to the textile field, and is particularly related to production methods of Flame-retardant antistatic blended yarn and its use.. The flame-retardant regenerated cellulose fibers are blended with flame-retardant acrylic fiber and nylon conductive fibers according to the weight ratio of 50-58: 40-48: 2. The production method include: cotton blending, blowing, cotton carding, and strip, knitting machine, spinning, and winding. The invention provides a flame-retardant and anti-static blended yarn which belongs to the middle count yarn, wherein the content of the silicon-nitrogen-based flame-retardant regenerated cellulose fiber is above 50%, solving the problem that the present technology cannot be produced when the content of the flame-retardant and regenerated cellulose fiber is high. The flame retardant and antistatic blended yarn provided by the invention has the advantages of high flame retardant and permanent flame retardancy, environmental protection, non-toxic smoke, excellent antistatic performance, natural and soft hand feeling, excellent wearability and moisture absorption and air permeability. It can be applied to special group clothing for individual protection, home textile, elderly, infant and so on.