Method for industrially preparing trimethyl indium

The invention relates to a method for industrially preparing trimethyl indium, The method is characterized by comprising the following steps: putting indium-magnesium alloy materials into a reaction kettle filled with inert gases; adding alkyl halide step by step while stirring in the presence of ether solvents; controlling the return velocity of the solvents by controlling the dropwise adding velocity of alkyl halide; vaporizing the solvents after the reaction is finished; obtaining the compound of trimethyl indium and ethers under the condition of reduced pressure; and finally decompoundingthe compound to obtain the trimethyl indium. The process is simple and steady in reaction, easy to control, high in reaction yield and very safe in reaction process as the raw materials adopted in the reaction process do not contain the materials liable to spontaneous combustion, thus being especially suitable for large-scale industrial production.