Method for producing low-grade aliphatic amine

The invention provides a method for producing low-grade aliphatic amine. In order to solve the problems that water generated by reaction or water in a raw material influence the efficiency of a catalyst and a large amount of non-condensable gas is generated to cause hydrogen waste and environmental protection pressure, ketone or alcohol serving as the raw material is contacted with ammonia gas in a fixed bed serving as a reactor at the reaction temperature of between 60 and 300 DEG C under the reaction pressure of 0.1 to 8.0MPa in the presence of hydrogen or hydrogen-containing gas under the action of the catalyst to generate C2 to C5 aliphatic amine through hydroamination reaction, wherein the catalyst comprises a carrier, metal active ingredients and a silane group which is grafted by silylation. Compared with the prior art, the method has the advantages that: reaction performance is not obviously changed when the hydrogenated raw material contains trace water and can be kept stable basically when water content is fluctuated; meanwhile, the generation amount of carbon deposit is small, and the catalyst has longer service life.