The invention aims to provide a vehicle-mounted Ethernet gateway test system and method so as to solve the problems of complex operation and low test efficiency in an Ethernet gateway test process inthe prior art. The vehicle-mounted Ethernet gateway test system comprises a tested Ethernet gateway, an upper computer and a bus acquisition device connected between the tested Ethernet gateway and the upper computer, the upper computer is used for receiving a test instruction input by a user through a human-computer interaction interface and sending a test case corresponding to the test instruction to the bus acquisition device according to the test instruction; and the bus acquisition device is used for testing the tested Ethernet gateway according to the test case and outputting a test result.