The invention provides a cavitation monitoring system and a pod driver. The cavitation monitoring system can comprise a pressure sensing device and a processing unit. The pressure sensing device is arranged at the surface of a rudder body of the pod driver and is configured to sense the pressure of liquid at the surface of the rudder body. The processing unit is configured to obtain the pressure of the liquid around the pressure sensing device according to the output of the pressure sensing device and determine whether the obtained pressure is less than or equal to a preset threshold value, wherein when the obtained pressure is determined to be less than or equal to the preset threshold value, the processing unit determines that cavitation will occur in the liquid, wherein the threshold value is equal to or greater than a critical pressure value at which the cavitation will occur in the liquid around the pressure sensing device. Thus, it is determined that cavitation will occur prior to the occurrence of cavitation, and therefore, the state of travel of a vessel is allowed to be actively or automatically changed to avoid the generation of cavitation.