Abstract: This paper presents the unsteady PSP measurements applied in high speed cascades. First, characteristics of fast response PSP are measured by calibration system and shock tube, the results show this paint owns low temperature sensitivity and submillisecond response time. The high-speed cascade test is conducted by employing pulse flow actuator to form active controllable unsteady flow on the surface of the blade, using fast response PSP and dynamic pressure sensor to measure the blade surface pressure simultaneously, and infrared technology to monitor the blade surface temperature. In respect of blade surface mean field, pulsation field and time-frequency in a single point, fast response PSP is in accord with pressure sensor. In addition, fast response PSP can display shock position and separation area dynamically.