The em bedded test terminals used in the electricity information acquisition test system are limited to the RAM space and the CPU processing ability, so the integral TCP/IP protocol is difficult to be used in the test terminals. A simplified TCP/IP protocol stack is designed for the electricity information acquisition test system. The simplified TCP/IP protocol stack can accomplish the basic communication of TCP/IP function including the ARP, ICMP, IP, UDP, TCP, the dynamic configuration of IP address, Client/Server mode switch and the MSS Buffer mechanism of TCP, but the RARP, IGMP and the sliding window mechanism of TCP which are otiose to the test terminals can be cut. The test results show that the protocol stack can accomplish the TCP/IP communication and satisfy the reliability and real-time property of the electricity information acquisition test system.