The invention relates to the technical field of mechanical dust collection, in particular to a water jet dust collector, which comprises a water tank, a non-pressure clear water delivery pipe, three one-way valves, a pressurized chamber, a piston, a connecting rod, a crankshaft, two pressure clear water delivery pipes, a pressure storage chamber, a dust collection conduit, a nozzle, a sewage delivery pipe, an eddy descaling chamber, a garbage collection chamber, a filter net and a sewage collection chamber. The water jet dust collector does not use energy resources such as electric energy and can be used under the condition that no power source is available; and with the adoption of the water jet dust collector, main power is formed mainly by depending on the condition that the crankshaft is rotated when the water jet dust collector is moved, so as to affect the connecting rod to drive the piston to pressurize water flow; the water flow is used as a carrier, which has better dust collection effect than gas flow; multiple filtration and collection are adopted in dust collecting aspect, and the dust can be better classified and collected, so that the dust collection effect is better, and the dust collection amount is larger; and the garbage collection chamber is designed into a spherical shape, is easy to clean and has no dirt-hiding corners.