The invention discloses a pig mycoplasma pneumonia live attenuated vaccine and application thereof. A pig lung disease material infected by typical pig mycoplasma hyopneumoniae and not infected by other pathogens is screened and then is subcultured to the 100th generation through the lung of a baby rabbit, then pig mycoplasma hyopneumoniae strains are separated and are continuously subcultured through a culture medium; meanwhile, the mycoplasma hyopneumoniae AN306 is obtained through screening of a plurality of strains, and the preservation number of the mycoplasma hyopneumoniae AN306 is CCTCC M2012431. The invention also relates to a pig mycoplasma pneumonia live vaccine preparation based on the preparation of the attenuated vaccine strain. The pig mycoplasma pneumonia live vaccine preparation comprises a live attenuated vaccine strain, a pharmaceutically acceotable carrier or auxiliary ingredient and an adjuvant, and further comprises immunogens of other pathogens. The pig mycoplasma pneumonia live vaccine disclosed by the invention can be immunized in multiple ways and can enable animals to gain protection ability for resisting pig mycoplasma hyopneumoniae infection.