The ultrasonic guided-wave technique is widely used in the inspection and evaluation of pipeline defects. The defects in pipeline are mainly corrosion defects, and the actual form of pipeline corrosion is diverse and complex. A large number of researches for pipeline corrosion waveguide detection are conducted by means of simulation. The common simplified defect models cannot fully present the complexity of the actual corrosions and the mistakes may be made when analyzing the signals with them. The work in this article proposes a corrosion defect simulation model based on W-M fractal function, and further studies the finite element modeling of the pipeline with corrosion for guided waves inspection. The model is evaluated by simulation results of inspecting different corrosion defects. Results show that the obtained reflections can provide more defect information, which are conducive to reveal the quantitative relationship between the characteristics of pipeline corrosion and the guided-waves signal. Research results of this work are expected to provide theoretical support for further research on the detection and evaluation of corrosion defects in pipeline.