A rotary-transmission-target microfocus X-ray source and an X-ray generation method based on the rotary-transmission-target microfocus X-ray source are provided. The X-ray source comprises a chamber, and an electron beam system is installed in the chamber. The electron beam system is arranged on a same side as an anode target rotating shaft. A motor in a rotary anode target system drives an anode target to rotate through a bevel gear transmission device. The microstructure of a target is designed. An electron beam emitted by the electron beam system vertically bombards the metal target of the rotating anode target. A cooling system is configured to cool the anode target.