The invention discloses a benzoindazole compound and its application. The benzoindazole compound is prepared by adding 1 mmol of toluenesulfonyl hydrozide into 3 ml of anhydrous methanol under nitrogen gas protection, slowly adding 1 mmol of 1-naphtenone into the solution drop by drop, adding 0.05 mmol of citric acid as a catalyst into the solution, carrying out a reaction process at the room temperature for 5h, carrying out concentration, separating a primary product through a silica gel column, adding 0.5 mmol of the primary product and 0.75 mmol of 2-(dimethylamino)malononitrile into 2 ml of DMF, adding 0.025 mol of Zn(OTf)2 and 0.025 mol of CoCl2 as catalysts into the solution, carrying out a reaction process at the room temperature for 10h, carrying out concentration and carrying outpurification through a silica gel column. The benzoindazole compound is used for preparation of an acetylcholinesterase inhibitor and a senile dementia treatment drug.