The work aims to predict surface potential distribution and corrosion rate of buried metal pipeline. The geometry model of crevice corrosion of metal pipeline was constructed, and the electrochemical reaction dynamic equation of corroded pipeline was derived by providing cathodic protection. Initial conditions and boundary conditions of geometric simulation model were constrained. MATLAB software was utilized to simulate the geometric model covering potential distribution law of cathodic protection and corrosion speed of surface crevice, and the simulation results were compared with experimental measurements to obtain relative error between the simulation results and experimental results. Bottom simulation potential of surface crevice corrosion in metal pipeline under cathodic protection increased reversely with the increase of the time, and the maximum potential in 50 h of polarization time was –8.6 V. Simulation potential of surface crevice corrosion in metal pipeline under cathodic protection decreased reversely with the increase of crevice depth, and the minimum potential at a distance within 10 cm from the crevice surface was -0.78 V. The simulated corrosion rate of surface crevice in metal pipeline under cathodic protection decreased gradually with the increase of time, and the minimum corrosion rate was 0.334 mm/a in the first 5 years. Meanwhile, the relative error between simulation value and experimental measurement was less than 5%. Hence the rectangular crevice model can be used to predict potential distribution of cathodic protection and corrosion rate of crevice surface, further reducing the corrosion rate of metal pipeline and preventing catastrophic accidents.