Aiming at the problem that the hydraulic conical throttle valve is easy to produce cavitation and has the characteristics of large temperature rise of throttle, and the influence of temperature effect on the development and change of cavitation can not be ignored, an experimental study was made on the influence of temperature effect on the cavitation shape in the conical throttle valve. The cavitation test system of conical throttle valve was built. In order to observe the cavitation of conical throttle valve conveniently, the experimental conical throttle valve was made of plexiglass, and the cavitation shape was collected by high-speed camera. Different temperature and pressure conditions were set up in the experiment. According to the acquired bubble images, it was determined that the initial bubble radius of the conical throttle valve was about 30μm. The increase of temperature would make the cavitation develop more fully. At the same time, the increase of temperature would reduce the restriction of hydraulic oil on the micro-nucleus. The number of bubbles produced was more and the cavitation was more obvious, and the cavitation in the conical throttle valve was obtained. At low strength, it was flaky cavitation, and with the increase of cavitation strength, it would be changed into cloud-like cavitation. To sum up, temperature had a very obvious effect on cavitation.