The two-stage adjustable turbocharging system has an extremely compact structure, the interference of air flow between the systems leads to a strong coupling effect, and hence the turbine performance changes. The interstage flow field measurement of two-stage adjustable turbocharging system was first discussed, the measurement method of turbine inlet flow field was explored in detail, and a fully automatic step measurement method based on X-type constant temperature hot-wire anemometer was designed. The swirl generated by the 35° swirl generator at the inlet of radial turbine was measured. The measurement results show that the magnitude of swirl angle keeps between 35° and 36° and is consistent with the deflection angle of swirl generator blade with the change of mass flow rate. In addition, the variation trends of swirl axial and tangential velocity are the same, which increases gradually from the pipe wall to the pipe center and reaches the maximum at the center of circle. Therefore, the feasibility and accuracy of X-type two-dimensional hot-wire is proved by measuring the swirl flow at the inlet of turbine, which provides the reference for the flow measurement method and pipeline structure optimization design of two-stage adjustable turbocharging system.