Preparation method of polyether amine

The invention provides a preparation method of polyether amine. By taking polyether polyol with an average molecular weight of 100-1000 as a raw material, under the action of hydrogen, an aminating agent and a supported metal catalyst, different kinds of catalysts are loaded into two sections of tubular reactors at different reaction temperatures to implement catalytic amination, so that aliphatic polyether amine is prepared. A co-precipitated metal catalyst is loaded into a first-section reactor, and meanwhile, the reaction temperature is controlled at 160-220 DEG C; and the supported metal catalyst is loaded into a second-section tubular reactor, and meanwhile, the reaction temperature is controlled at 200-250 DEG C. By sectionally adopting different active catalysts and different reaction temperatures, the amination processes of different active constituents in the polyether polyol are controlled, and a situation that low-molecular-weight polyether generates dimethylmorpholine by-products in the process of amination is inhibited, thereby greatly improving the selectivity and yield of polyether amine products. The prepared polyether amine is extremely light in appearance color, and suitable for industrialization.