Aiming at problems that the critical techniques and vehicle spare parts completely dependent on import in domestic rail transit of linear induction motor (LIM) traction drive, as well as the difficulties of repair maintenance, and the high costs of vehicle operation, a highpower, forced aircooled LIM traction converter system was researched and developed with completely independent intellectual property rights. Against the end effect and other problems caused by the special structure of LIM, an optimal scheme of indirect fieldoriented vector control was proposed. And the change of LIM secondary time constant had a great influence on the fieldoriented control, which results in torque performance degradation. Therefore an online parameter identification method based on the minimum current was presented. It had advantages of simple calculation and not relying on other motor parameters. Experiment results of test bench demonstrate the accuracy and validity. The experiments results in an actual operation subway line showed that the performance of localization traction converter fully meets the vehicle technical requirements. And some indicators such as efficiency were even better than the imported one.