The invention discloses a building method for a liver cancer rat model. The method comprises the steps that 1, animals are included, wherein the clean class is Wistar, the number of male rats is 40, the weight is 150+/-20 g, and the male rats are randomly divided into an experimental group including 30 rats and a control group including 10 rats; the animals are reared in a semi-barrier system according to the raising requirement of the clean class of the animals; 2, modeling is performed, wherein sterile tap water is used for preparing a diethylnitrosamine solution with the concentration being100 microgramPml (the solution is kept in a dark place and freshly prepared), the solution is freely drunk by the rats in the experimental group, the solution is changed one time every day, after three months, the solution is replaced with ordinary sterilization tap water, observation continues to be performed for 2 months, and the whole experimental process lasts 5 months; according to the control group, the rats drink the sterilization tap water in the whole experiment process; 3, liver cancer is determined; 4, liver tissue is sampled. A clinic sample is adopted for performing positioning and quantified expression verification, the evidence related clinically is found, the clinic value is evaluated, and the novel clue is provided for liver cancer pathogenesis and liver cancer mechanismresearch. The liver cancer key molecule screened by a question for discussion is adopted for researching a liver cancer marker related to early discovery, classification and evaluation prognosis, andthe research basis is laid for selecting a more effective and accurate liver cancer treatment target position.