Friedel-Crafts reaction of 3-methylindoles and imines catalyzed by diphenyl phosphate can be used to synthesize 2-indolyl methanamines in one step, which has a wide range of pharmacological activities. The reaction conditions were optimized and the optimal reaction conditions were obtained as follows: n (3-methylindoles) ∶ n (imines) ∶ n（diphenyl phosphate） = 1.0 : 2.0∶0.1, the amount diphenyl phosphate is 0.0025 mmol, 1 mL anhydrous dichloromethane as solvent, room temperature, reaction time 0.5 h. 2-indolyl methanamine derivatives can be obtained in good yields (85~90%). The structures of the products were confirmed by 1HNMR, 13CNMR and HRMS.