An inorganic low melting solid binder and its preparation method

The invention discloses an inorganic solid binder and a preparation method thereof. The composition formula of the binder is as follows: nCaO.mBaO.xP2O5.yB2O3, wherein in the formula, n is larger than or equal to 0.8 and less than or equal to 1.1, m is more than or equal to 0.1 and less than or equal to 0.5, x is larger than or equal to 0.1 and less than or equal to 0.5, and y is larger than or equal to 0.3 and less than or equal to 1.0. The inorganic solid binder disclosed by the invention has fine particles and stable chemical property in suspension, starts to fuse at the temperature of about 300 DGE C, is completely fused at the temperature of 500+/-50 DEG C, takes a bonding effect, and is especially suitable for a temperature interval of 500-600 DEG C in a lamp craft bake tube manufacturing process. The preparation method is a chemical coprecipitation method which has a simple production process and is easy to industrialize.