Liquid phase microextraction（LPME） is a miniature environmental friendly sample pre-treatment technology， which integrates extraction， enrichment and concentration. It is of great significance to the whole chemical field， especially in the field of food analysis. It has become a research hotspot of sample pretreatment technology. LPME overcomes the disadvantages of traditional methods and has the advantages of less organic reagent， simple and fast operation and high enrichment factor. Based on LPME， the preprocessing technology is also being developed and applied continuously. By summarizing the principle of LPME and its application in food analysis， the advantages and disadvantages of different preprocessing technologies were discussed and their future development trend was prospected.