Solid lipid nanoparticles （SLN） is a solid colloidal drug delivery system based on natural or synthetic solid lipids embedded in lipophilic nuclei or coated on lipopolipid surfaces. The particle size of SLN is 10~1 000 nm. The carriers used in solid lipid nanoparticles are lipid-like compounds with low toxicity，good biocompatibility and biodegradability. It is a new generation of submicron drug delivery system developed in the early 1990s. Solid lipid nanoparticles have the advantages of controlling drug release，avoiding drug degradation or leakage，and good targeting. This paper summarized and analyzed the research progress of solid lipid nanoparticles，including the basic components，preparation methods，factors affecting drug loading （DL） and encapsulation efficiency （EE），drug delivery system release，the application and advantages of solid lipid nanoparticles.