The invention provides a model for simulating penetration depth of injected ions in a light resistor and a modeling method of the model. The formula of the model is shown in the description, wherein f(x,y) is the thickness of the ions injected in the light resistor, g (x,y) is the thickness of the ions injected in a silicon substrate, y is the injected energy, x is the type of the injected ions, and AMU(x) is the atomic weight of the element x. According to the model for simulating the penetration depth of the injected ions in the light resistor and the modeling method of the model, the depth of the ions injected in the light resistor can be calculated, and adaptive resistors are selected aiming at different ion injecting conditions, so that resistor penetrating is prevented.