Disclosed is a portable teeth cleaning apparatus, which implements, through a pump in a teeth cleaner, a function of supplementing a teeth cleaning liquid from a connecting seat connected to the teeth cleaner. Therefore, it is no longer necessary to connect the teeth cleaner to a teeth cleaning liquid source through a connecting hose during teeth cleaning, and liquid leakage is avoided during liquid supplement. Further, a seating/unseating status and whether a liquid reservoir is filled up are detected automatically, and a controller controls on/off and switching of a series of valves, thereby implementing automatic liquid supplement of the teeth cleaner.