Air-tank-free positive and negative pressure generation system and inkjet printer

The embodiment of the invention relates to the technical field of ink-jet printing, and discloses an air-tank-free positive and negative pressure generation system which comprises a control unit and a pressure generation unit. The control unit is used for receiving a feedback signal of the printing unit, sending a pressure control signal to the pressure generation unit according to the feedback signal, and performing ink overflow protection on the printing unit according to a first ink overflow probe signal of the printing unit; the pressure generating unit comprises an air pump used for providing positive and negative air pressure for the printing unit; the air inlet and outlet electromagnetic valve is used for adjusting the working mode of the pressure generation unit into a positive pressure air outlet mode or a negative pressure air exhaust mode; the sealing electromagnetic valve is used for controlling opening and closing of a gas circuit; the pressure generating unit is connected with the printing unit