Aluminum phosphate sol and preparation method thereof

The invention relates to aluminum phosphate sol and a preparation method thereof. The aluminum phosphate sol contains the following components in percentage by mass: 10%-50% of Al2O3, 0.5%-10% of soluble salt with an anion of C6H7O7 or CH2COO or HCOO and 1.5%-15% of P. The preparation method comprises the following steps: (1) stirring pseudo-boehmite, the soluble salt with the anion of C6H7O7 or CH2COO or HCOO and deionized water, and standing; and (2) uniformly stirring the slurry obtained in the step (1), and adding phosphoric acid or a mixture of phosphoric acid and phosphate. The aluminum phosphate sol is used for preparing a catalyst, so that the environmental pollution caused by chloride ions and nitrate ion is avoided; the aluminum phosphate sol can be directly used as a bonder of a catalytic cracking catalyst; and the heating is not required during the preparation, a preparation process is simple, high in phosphorus-aluminum ratio, the range is adjustable, and the industrial production is easily realized.