The invention relates to a preparation method of a 2-type diabetic nephropathy model. The method comprises the following steps of: selecting a male SHR (spontaneously hypertensive rat) rat with an age of 6 weeks, wherein the blood pressure of the male SHR rat at birth is normal, and at the time of 4 weeks, the blood pressure begins to rise; after adaptively feeding the SHR rat selected in the step (1) for one week, feeding a high sugar and high fat feed for 2 weeks; detecting the weight, the blood fat, the blood sugar and the insulin concentration and calculating an insulin resistance index evaluated by a steady-state model, wherein the insulin resistance index is not smaller than 3.8, and the high fat and high sugar feed comprises the following components in percentage by weight: 10.0 percent of lard, 20.0 percent of cane sugar, 2.5 percent of cholesterol, 2.0 percent of cholate and 66.5 percent of conventional feed; after fasting the insulin resistant SHR rat for 12 hours, carrying out a small-dose one-time STZ (streptozocin) (35mg/kg) intraperitoneal injection on the SHR rat, wherein the small dose is 35mg/kg; after 72 hours, measuring the random blood sugar; and judging the 2-type diabetic nephropathy model to be successfully prepared if the plasma glucose is not smaller than 16.7mmol/L.