A vacuum suction apparatus includes a cup body, an adjust member, and a seal assembly. Therein, the cup body is hollowed with two penetrable ends, having a neck portion disposed with penetrable first and second openings at both ends thereof, while the first opening is combined with a joining member. The adjust member is screwed to the joining member. The seal assembly has an upper partition, a lower partition, and a membrane, cooperating with the adjust member to allow the air to pass through the upper partition, the lower partition, and the adjust member. A negative pressure is produced due to the seal function of the membrane, such that a male genital organ reciprocates to feel the force of withdrawing and pushing. The forces are adjustable with the adjust member, and the user is able to control the speed of the apparatus reciprocation.
