The invention relates to veterinary valnemulin, a novel liposome formulation of the salt thereof and a preparation method thereof, which belongs to the field of veterinary antibiotic preparations. In the preparation, valnemulin and the salt thereof serve as the main components, phospholipid and cholesterol serve as membranes, and the common liposomes, the lung targeting liposomes or the long circulating liposomes of valnemulin or valnemulin salt can be prepared. The valnemulin and the liposomes of the salt thereof have better tissue selectivity compared with the common preparation, are effective to the bacterial and mycoplasma infection in cells, and can reduce the toxic and side effect. The lung targeting liposomes targets the medicine to the lung, and has significant effect to the mycoplasma infection of the lung, bacterial infection and the like, and reduces the toxic and side effect. The long circulating liposomes significantly improves the circulation time of the liposomes in thebody, so that the medicines displays the efficacy for a longer time more effectively, so s to reduce the delivery times and the dosage.