The invention discloses a novel preparation and continuous production method of melamine resin. The melamine resin comprises 0-5 parts of water-soluble modified organic silicon, 0-10 parts of fluorinated polyol, 10-50 parts of melamine, 20-50 parts of formaldehyde, 5-30 parts of modifier, 0.1-5 parts of combined phase transfer catalyst, 10-50 parts of desalted water, and 0-20 parts of sodium hydroxide. The preparation and continuous production method includes the steps of firstly, mixing the materials; secondly, quantitatively conveying for feeding the materials; thirdly, heating for polycondensation; and fourthly, cooling and controlling temperature. The melamine resin produced by the preparation and continuous production method is long in shelf life, high in dispersibility, less prone to caking, stable in performance and the like, and is quite applicable to stable production of melamine resin foamed plastic by an industrial microwave and melamine resin fiber by spinning of a screw machine from melamine resin.