The invention provides a method and a device for transmitting data, and a process method and a device for receiving data, belonging to the field of communication. The method for transmitting the data comprises the steps of: ensuring data structure corresponding to data to be transmitted, ensuring command type and data length, memorizing current data according to the appointed mode of an data packet when firstly transiting the data in the data structure, and transmitting the current data by the means of TCP, wherein the appointed mode of the data packet comprises an command packet head and the current data, and the command packet head carries the command type and the data length. By adopting the appointed mode of the data packet to transmit the data, the invention leads the receiving party to be capable of correctly packaging the received data packet based on the length, and reliably transmitting the data with sequence and structural information.