Highly airtight gas pump

A highly airtight gas pump, which can be driven by a motor for gas charging and discharging, the gas pump comprising:

• a gas suction member having a gasbag holder and a gasbag, the gasbag holder having a receiving hole and a pore, the gasbag having a plate, a hollow retractable portion, an intake valve, and a flexible tube, the plate being fixed to the gasbag holder, the hollow retractable portion extending outwardly from one of two sides of the plate and received in the receiving hole of the airbag holder for being driven by the motor to move between an oppression position and an expansion position, the intake valve being mounted to the plate and movably covering the pore of the gasbag holder, the flexible tube extending outwardly from the other side of the plate and having at least two crosscuts, the flexible tube being divided into at least two vent valvular pieces by the two crosscuts, each of the vent valvular pieces having a reinforcing strip formed on an internal wall thereof and being movable inwardly by the air inside the hollow retractable portion;
• and
• a gas exhaust member covered on the gasbag of the gas suction member and having a venthole and a guide slot, the venthole communicating with the hollow retractable portion for receiving the flexible tube therein, the guide slot communicating with the hollow retractable portion and the intake valve, the guide slot being used for guiding the air inside the intake valve into the hollow retractable portion.