The invention discloses a spray coating type fire-retardant antistatic polyurethane elastomer and a preparation method thereof. The spray coating type fire-retardant antistatic polyurethane elastomer comprises an A component and a B component, wherein the A component is composed of 40-60 parts of isocyanate and 40-60 parts of phosphorus-containing flame-retardant polyol, and the B component is composed of 0-30 parts of chain extender, 0-30 parts of polyether polyol, 10-75 parts of amine-terminated polyether, 0-30 parts of carbon nanotube slurry, 0-3 parts of pigment and 0-3 parts of assistant. The preparation method comprises the following steps: adding the phosphorus-containing flame-retardant polyol into a reaction kettle, heating up to 110 DEG C, vacuumizing for 3 hours, cooling to 30 DEG C, adding the isocyanate, heating up to 105 DEG C, and reacting for 3 hours to obtain a semi-prepolymer A component; sequentially adding the ingredients of the B component into a stirring tank, stirring uniformly, and grinding the mixture in a sand mill for 2.5 hours to prepare the B component; spray-coating the A component and the B component onto a surface through a high pressure spray coating machine, and quickly curing to form. According to the spray coating type fire-retardant antistatic polyurethane elastomer disclosed by the invention, film forming matters are stable, no fire retardant is separated out and the durability is good; a spray coating type fire-retardant antistatic material prepared by the preparation method disclosed by the invention has both fire resistance and anti-static function, so that the material is suitable for application on flame-retardant and explosion-proof occasions.