The invention discloses a testing device for detecting a high-pressure rotating well-washing tool, and the device comprises an upper connector, a fixed frame, a protection sleeve, a pressure sensor, and a rotating speed sensor. The upper connector is connected with a detected high-pressure rotating well-washing tool, and is fixed in a central hole of the fixed frame. The fixed frame, the pressure sensor and the rotating speed sensor are respectively disposed at corresponding positions of the protection sleeve. Aiming at a condition that the current testing of the high-pressure rotating well-washing tool in China is at a theoretical calculation level, the device and method can provide real and effective reference for the operating state and effect of the tool in a well through the strict testing of the flushing force and rotating speed. The device provides the support for the selection of corresponding types of high-pressure rotating well-washing tools according to different well conditions, and the support for the design improvement of the tools.