The invention discloses high-purity ultrafine spherical quartz powder, a preparation method and special equipment thereof. In the quartz powder, the content of SiO2 is not lower than 99.80 percent, granularity is between 1 and 40 mu meters, sphericization ratio is between 90 and 100 percent, and non-crystalline ratio is between 99 and 100 percent. The preparation method is to axially introduce a quartz raw material into flame at a temperature not lower than 1750 DEG C from a flame burner, melt the quartz raw material in a sphericizing furnace, and classify and collect the quartz powder after cooling to obtain a product. The equipment comprises a powder feeder, the flame burner connected with the powder feeder, a sphericizing furnace in axial connection with the flame burner, a water cooling device encircling the periphery of the lower part of the sphericizing furnace, a gravitational settler connected with the bottom of the sphericizing furnace, a cyclone collector communicated with the upper part of the sphericizing furnace, a cloth collector connected with the top part of the cyclone collector, an exhaust fan connected with the cloth collector, and a water tank connected with theexhaust fan. The quartz powder has high purity, high sphericization ratio, high non-crystalline ratio, simple equipment and process and low cost.