A new vision probe based on telecentric photography has been developed for multiphase system measurement. Four outstanding advantages of the probe are as follows: (i) Sharp pictures with little image distortion can be obtained because of the distinctive parallel light paths from the telecentric lens. (ii) The slim probe can be inserted everywhere in large reactors. (iii) Local characteristics such as particle (solid particle or drop or bubble) size, holdup, and interfacial area with one or even more dispersed phases can be measured. (iv) The higher holdup of the dispersed phase is allowed. The robustness of the probe has been tested in a multiphase reactor. Finally, applications in solid-liquid, gas-liquid, and gas-liquid-solid stirred tanks are present respectively to demonstrate the measurements on the particle holdup, bubble size, and particle and bubble size using this vision probe.