There exists surge problem for turbocharged diesel engine in the transient process, which affects reliability and driving experience. The surge problem needs to be solved urgently, especially for China Ⅵ turbocharged diesel engine that uses intake throttle valve to improve thermal management performance. A heavyduty truck engine with a displacement of 10.5 L was used to conduct a throttle sudden drop test at different speeds. By comparison, it was found that the engine is more prone to surge in the process of throttle sudden drop at medium and low speeds. The throttle sudden drop test was further conducted based on different inlet throttle valve closing speeds and minimum closing openings in thermal management mode. By comparing the surge law, the fast closing speed of the inlet throttle valve would lead to the stronger blocking effect of intake, the small minimum opening would lead to the smaller minimum folded flow, and the risk of surge hence became large. Then the surge strategy was proposed based on air system model and was verified. The results show that the surge strategy in thermal management mode can effectively prevent overpassing the surge line in the process of throttle sudden drop, which solves the surge problem of China Ⅵ  turbocharged diesel engine that using the intake throttle valve to some extent.