In order to improve the testing efficiency and the reusability of the test script, a relay protection automatic test platform based on distributed design and test function is proposed. On the basis of the analysis of intelligent substation relay protection device characteristics and test platform requirement, this paper proposes a design scheme which takes digital tester for main platform of automatic test system and implements test function expansion through a distributed architecture. Through the semantic and grammatical rules and feature dictionary definition in test scripts, virtual test script editing and generating are realized. When the tests are performed, an instantiation test script with a certain object and performability is generated by virtual test script information secondary mapping to improve the reusability of test script. The practical application results show that the system can improve the testing efficiency of relay protection device, allow the test script to be reused across devices, and increase the practical application value of the automatic test platform.