A data transmission method, device, conference system, wireless screen transmitter and storage medium are provided. According to the data transmission method, when the wireless screen transmitter accesses the terminal apparatus and performs screen transmission on the display apparatus, the privacy recognition program is quickly loaded from the wireless screen transmitter to the terminal apparatus. While transmitting corresponding media data to the wireless screen transmitter in real time according to current display screen, the terminal apparatus runs the privacy recognition program to recognize a privacy window in the current display screen and acquires corresponding position information, and then sends the position information to the wireless screen transmitter.