A method for controlling a smart device by voice, which is implemented by a control device, comprising: reading, with a software application associated with smart devices, information of the smart devices; determining, based on the information, multiple smart devices having voice recording function from the smart devices; determining multiple to-be-started smart devices located in different positions from the multiple smart devices having voice recording function; sending a startup instruction to the multiple to-be-started smart devices to start up their voice recording functions; after the sending, receiving voice data respectively from the multiple to-be-started smart devices located in different positions; processing the multiple voice data by using a beam-forming technology to obtain optimized voice data; controlling, based on the optimized voice data, a smart device that corresponds to the voice data, wherein the determining multiple to-be-started smart devices from the multiple smart devices having voice recording function comprises: determining a user's location based on positioning technology; obtaining locations of the multiple smart devices having voice recording function from prestored data; and determining the smart devices having voice recording function located within a preset range including the user's location as the multiple to-be-started smart devices, wherein the controlling, based on the optimized voice data, a smart device that corresponds to the voice data comprises: sending the optimized voice data to an infrared remote control device so that the infrared remote control device searches for a corresponding control instruction based on voice information in the optimized voice data, searches for a corresponding infrared code based on a device name in the optimized voice data, and sends the control instruction to a smart device corresponding to the infrared code. reading, with a software application associated with smart devices, information of the smart devices; determining, based on the information, multiple smart devices having voice recording function from the smart devices; determining multiple to-be-started smart devices located in different positions from the multiple smart devices having voice recording function; sending a startup instruction to the multiple to-be-started smart devices to start up their voice recording functions; after the sending, receiving voice data respectively from the multiple to-be-started smart devices located in different positions; processing the multiple voice data by using a beam-forming technology to obtain optimized voice data; controlling, based on the optimized voice data, a smart device that corresponds to the voice data, wherein the determining multiple to-be-started smart devices from the multiple smart devices having voice recording function comprises: determining a user's location based on positioning technology; obtaining locations of the multiple smart devices having voice recording function from prestored data; and determining the smart devices having voice recording function located within a preset range including the user's location as the multiple to-be-started smart devices, wherein the controlling, based on the optimized voice data, a smart device that corresponds to the voice data comprises: sending the optimized voice data to an infrared remote control device so that the infrared remote control device searches for a corresponding control instruction based on voice information in the optimized voice data, searches for a corresponding infrared code based on a device name in the optimized voice data, and sends the control instruction to a smart device corresponding to the infrared code. determining a user's location based on positioning technology; obtaining locations of the multiple smart devices having voice recording function from prestored data; and determining the smart devices having voice recording function located within a preset range including the user's location as the multiple to-be-started smart devices, wherein the controlling, based on the optimized voice data, a smart device that corresponds to the voice data comprises: sending the optimized voice data to an infrared remote control device so that the infrared remote control device searches for a corresponding control instruction based on voice information in the optimized voice data, searches for a corresponding infrared code based on a device name in the optimized voice data, and sends the control instruction to a smart device corresponding to the infrared code.