Provided is a liquid discharge device provided with a ball thrust bearing and a sliding conical bearing. The liquid discharge device comprises a pressure air supply device (7), a pressure chamber (8), a pressure supply pipe (9), a liquid discharge pipeline (10) and an obtaining and filtering device (20), wherein the pressure air supply device (7) is used for providing pressure for the pressure chamber (8) through the pressure supply pipe (9), the pressure chamber (8) can pressurize liquid inside the pressure chamber (8) and send out the liquid through the liquid discharge pipeline (10), the obtaining and filtering device (20) is arranged at the inner side end of the liquid discharge pipeline (10) and is used for filtering the liquid when the liquid discharge pipeline (10) obtains the liquid from the pressure chamber (8), the outer side end of the liquid discharge pipeline (10) is used for sending out the liquid in a flowing mode, and a liquid inlet (81) is formed in the top of the pressure chamber (8).