A pet water fountain comprises a bucket, a pump, a cover body, a filter, a water platform and a flower nozzle, wherein the cover body is covered on the bucket, the filter is contained in a first recess formed in the center of the cover body, and a first hollow pipe extends from the bottom of the first recess into the bucket; the water platform has a second hollow pipe extending downwards to go through the first hollow pipe to connect a pump outlet of the pump, and has an inner flange higher than an outer flange, and further has an outer sidewall extending downwards to being supported on a first step surrounding the top of the first recess; the flower nozzle has a plurality of spouts and a third hollow pipe extends downwards from the center of the flower nozzle to be inserted into the second hollow pipe.