Jeff Bezos almost kissed the ground before Katy Perry and Gayle King ... because he tripped and fell on his face at the Blue Origin rocket launch landing ... and it's all on video.

Ya gotta see the footage ... the billionaire, who founded Blue Origin, faceplants as he runs around the space capsule looking for fiancée Lauren Sanchez.

Jeff's peering in the windows and he's not looking where he's going ... and boom, he walks into a a ditch and trips over himself.

Bezos gets right up and continues to the door, where he helps open the latch and welcomes Lauren and the rest of her spaceflight buddies back to Earth.

Katy and Gayle both got down on their knees and kissed the Earth after their 11-minute trip to space and back ... and Jeff almost beat 'em to it. Fortunately, the guy is jacked and he was able to break his fall with his arms, stopping his face from making contact with the ground.

Jeff's living proof ... never skip arm day!!!