A pet water fountain (100, 200) comprising: a bucket (110, 210) configured to hold water; a pump (120, 220) positioned in the bucket (110, 210); an upper tray (130, 230); a water storage tray (150, 250) on top of the upper tray (130, 230); a filter (140, 240) being arranged between the upper tray (130, 230) and the water storage tray (150, 250); and a flower nozzle (160, 260) supported on top of the water storage tray (150, 250); wherein a pump outlet (122, 222) of the pump (120, 220) communicates with a water inlet (152, 251) of the water storage tray (150, 250); water in the bucket (110, 210) is pumped upwards from the pump outlet (122, 222) into the water inlet (152, 251) of the water storage tray (150, 250), and then into the flower nozzle (160, 260), and then falls on the water storage tray (150, 250) from the flower nozzle (160, 260), and then flows from the water storage tray (150, 250) to the upper tray (130, 230) after being filtered by the filter (140, 240) and back into the bucket (110, 210); wherein the upper tray (130, 230) has a lap edge (132, 231) supported on a top of the bucket (110, 210), and a recess (133, 232) is formed in the center of the upper tray (130, 230), with a first hollow pipe (135, 233) being located in the center of the recess (133, 232), and a plurality of through holes (136, 234) being formed on the recess (133, 232) around the first hollow pipe (135, 233); the filter is (140, 240) contained in the recess (133, 232) surrounding the first hollow pipe (135, 233); the water storage tray (150, 250) has a second hollow pipe (152, 251) extending downwards to go through the first hollow pipe (135, 233) to connect the pump outlet (122, 222); the flower nozzle (160, 260) has a plurality of spouts along its periphery and has a third hollow pipe (161, 261) extending downwards from the center of the flower nozzle (160, 260) to be inserted into the second hollow pipe (152, 251) of the water storage tray (150, 250), and the flower nozzle (160, 260) further has a top cover covering on the top of the third hollow pipe (161, 261); water in the bucket (110, 210) is pumped upwards from the pump outlet (122, 222) into the second hollow pipe (152, 251) of the water storage tray (150, 250) and then into the third hollow pipe (161, 261) of the flower nozzle (160, 260) and then flows out from the spouts. a bucket (110, 210) configured to hold water; a pump (120, 220) positioned in the bucket (110, 210); an upper tray (130, 230); a water storage tray (150, 250) on top of the upper tray (130, 230); a filter (140, 240) being arranged between the upper tray (130, 230) and the water storage tray (150, 250); and a flower nozzle (160, 260) supported on top of the water storage tray (150, 250); wherein a pump outlet (122, 222) of the pump (120, 220) communicates with a water inlet (152, 251) of the water storage tray (150, 250); water in the bucket (110, 210) is pumped upwards from the pump outlet (122, 222) into the water inlet (152, 251) of the water storage tray (150, 250), and then into the flower nozzle (160, 260), and then falls on the water storage tray (150, 250) from the flower nozzle (160, 260), and then flows from the water storage tray (150, 250) to the upper tray (130, 230) after being filtered by the filter (140, 240) and back into the bucket (110, 210); wherein the upper tray (130, 230) has a lap edge (132, 231) supported on a top of the bucket (110, 210), and a recess (133, 232) is formed in the center of the upper tray (130, 230), with a first hollow pipe (135, 233) being located in the center of the recess (133, 232), and a plurality of through holes (136, 234) being formed on the recess (133, 232) around the first hollow pipe (135, 233); the filter is (140, 240) contained in the recess (133, 232) surrounding the first hollow pipe (135, 233); the water storage tray (150, 250) has a second hollow pipe (152, 251) extending downwards to go through the first hollow pipe (135, 233) to connect the pump outlet (122, 222); the flower nozzle (160, 260) has a plurality of spouts along its periphery and has a third hollow pipe (161, 261) extending downwards from the center of the flower nozzle (160, 260) to be inserted into the second hollow pipe (152, 251) of the water storage tray (150, 250), and the flower nozzle (160, 260) further has a top cover covering on the top of the third hollow pipe (161, 261); water in the bucket (110, 210) is pumped upwards from the pump outlet (122, 222) into the second hollow pipe (152, 251) of the water storage tray (150, 250) and then into the third hollow pipe (161, 261) of the flower nozzle (160, 260) and then flows out from the spouts.