The invention provides a method for transmitting control information in a wall splicing system and a wall splicing system. The control information is transmitted through embedding the control information in a video signal; the method specifically comprises the steps of using a CTL (Complementary Transistor Logic) signal as an indicating signal of the control information and the video signal and transmitting the control information in a video signal field blanking area. According to the method for transmitting control information in the wall splicing system and the wall splicing system, provided by the invention, the control information is embedded into the video signal to finish the transmission of the control information so that the wiring complicatedness of the wall splicing system can be largely simplified, the same transmission speed with the video data can be kept for the control information, the communication speed of the system is largely increased and the response time of the system is accelerated.