Disclosed are a communication method for a wireless local area network, a station point and a communication system. The method comprises: receiving a control frame broadcast by a second station point, the control frame carrying a signal-to-noise ratio margin of the second station point, and the second station point being a station point, having competed for a communication channel, in a basic service set; acquiring a transmission path loss value of a communication link from the second site to a first site according to a receiving power of the control frame and a transmitting power with which the second site transmits the control frame; determining an upper limit value of the transmitting power according to the transmission path loss value and the signal-to-noise ratio margin of the second site; and sending or not sending a data packet for a target station point in the basic service set where the first site is located according to the determined upper limit value of the transmitting power. By means of the present invention, the spectrum utilization ratio is improved.