The invention discloses a method and system for testing a TTL-to-ECL level shifter. The method comprises the following steps: adding an auxiliary power supply to the power supply setting module of a test system and setting the pin configuration of the auxiliary power supply; setting a voltage value, a current-limiting parameter and a delay parameter of the auxiliary power supply in the corresponding power supply setting module; connecting the corresponding interface of the level shifter to be tested to the test system, and connecting the output interfaces of the level shifter to be tested to the auxiliary power supply via resistors; creating a test process of the level shifter to be tested according to a test requirement, and selecting a corresponding test method to test the level shifter in the test system. The method and system for testing the TTL-to-ECL level shifter may satisfy the test requirements of the level shifter by using the auxiliary power supply and setting the corresponding parameters so as to achieve various tests of the level shifter and improve the stability and reliability of the level shifter performance test.