The embodiment of the invention discloses a data transmit method, which comprises calculating transmission delay when data waiting to be transmitted is transmitted to a receiving terminal; and when the transmission delay is smaller than minimum delay threshold, transmitting the data waiting to be transmitted, when the transmission delay is larger than maximum delay threshold, discarding the data waiting to be transmitted, and when the transmission delay is between the minimum delay threshold and the maximum delay threshold, treating the data waiting to be transmitted by adopting a probabilitypacket loss method. Accordingly, the embodiment of the invention also discloses a data treatment device and a communication system, which can effectively reduce the transmission delay of business data and satisfy the business requirement of low delay.