Preparation method of silica sol with special morphology, silica sol with special morphology and product

The invention relates to a preparation method of silica sol with special morphology. The preparation method comprises the following steps: taking an RnSi (OR) 4-n solution as a silicon source; r is alkyl or alkylene or-CHOHCH2, and n is 0-2; the preparation method comprises the following steps: mixing one or more than two of RSi (OR) 3, (R) 2Si (OR) 2 and Si (OR) 4 in proportion to obtain a solution A; adding water into the solution A, dropwise adding a first catalyst, and heating for reaction to obtain a micromolecular silica sol solution; the prepared micromolecular silica sol solution is used as a seed solution, a structure-directing agent is added, a second catalyst is added, and heating reaction is performed to prepare the silica sol with a special morphology structure. According to the method, the special-morphology silica sol with high concentration and high purity can be prepared, the particle size of the prepared silica sol particles reaches 50-200 nm, the particle size of other ions is smaller than