Disclosed is an out-of-vat liquid filter for ensuring reliable connection of a water pipe connector, comprising a liquid filtration tank and the water pipe connector. The water pipe connector comprises two water pipe connecting bases, a valve driving shaft, a latch tongue, a driving device with two degrees of freedom, and a handle. The latch tongue is driven by the driving device with two degrees of freedom to rotate about an axis of a first degree of freedom, thereby sliding into or our of a latch catch. The valve driving shaft is driven by the driving device with two degrees of freedom to rotate about an axis of the second degree of freedom, thereby opening or closing the water pipe connecting base in which each valve is located. As a result, the valves can be open only after the water pipe connector is securely connected to the liquid filtration tank, and water pipe connector can be removed from the liquid filtration tank only after the valves are closed, thus effectively preventing water streams from leaking to the outside and improving reliability of the water pipe connector.
