Abstract: Disclosed are a nozzle structure and an oral irrigator thereof. The nozzle structure includes a base and a nozzle connected to the base. The base is provided with a receiving groove, and a whitening agent is provided inside the receiving groove. The base is provided with a water inlet channel communicated with the receiving groove. The nozzle is provided with a water outlet channel configured to facilitate outflow of whitening liquid, and a filter screen for filtering the whitening liquid is installed at one side of the water outlet channel.