The present invention relates to the field of biomedicine, and specifically relates to a contrast agent film-forming agent composition, a contrast agent film-forming lipid solution containing the contrast agent film-forming agent composition, and a contrast agent containing the contrast agent film-forming lipid solution and a preparation method therefor. The contrast agent film-forming agent composition comprises a lipid, an emulsifier and a surface charge modifier. Relative to 100 parts by weight of the lipid, the content of the emulsifier is 20-50 parts by weight, and the content of the surface charge modifier is 10-35 parts by weight, wherein the lipid is a carboxylated phospholipid, and the surface charge modifier is a polyelectrolyte. By means of the composition and the preparation method, nano-droplets of the obtained contrast agent can have a more uniform particle size, higher stability and better controllability, have a lower ultrasonic gasification threshold value, and same can also be used as a photoacoustic contrast agent or a multi-modal contrast agent, and has a wide application prospect.