The invention relates to a high-activity heavy distillate oil hydrotreatment catalyst preparation method which includes the steps: selecting VIII-group metal nickel soluble salt and polyhydroxy acid complexing agents to prepare acid solution; selecting VIB-group metal molybdenum soluble salt and alkaline precipitants to prepare alkaline solution; mixing large pore volume pseudo boehmite, nanometer titania powder and silica sol to form suspension slurry serving as a substrate, merging flow, adding the acid solution and the alkaline solution, performing closed reaction, uniformly dispersing metal components in titanium-silicon-aluminum media, performing filtration and washing to obtain catalyst precursor filter cakes after reaction, and curing, forming, drying and roasting the catalyst precursor filter cakes to obtain finished catalysts. Compared with bulk phase hydrogenation catalysts prepared by an existing method, the catalysts prepared by the method have the advantages of high mechanical strength, low abrasion, large pore volume, high metal dispersity, good hydrogenation activity, long service life and the like, and are particularly suitable for hydrotreatment of inferior heavy distillate oil which is high in sulfur-nitrogen content, large in polycyclic aromatic hydrocarbon proportion and difficult to process.