The present disclosure relates to a 5G or pre-5G communication system to be provided for supporting a data transmission rate higher than that of a 4G communication system such as an LTE. The present invention relates to a method by which a proxy sets an initial window value in a wireless communication system, the method comprising: splitting a transmission control protocol (TCP) connection between a terminal and a server; extracting the information related to the terminal from the data received from the terminal; and setting the initial window value on the basis of a round trip time (RTT) value and a throughput value for each of terminal groups grouped on the basis of the information related to the terminal.