It is the fact that the optimization of antenna tilt angle at base station is necessary for all cellular networks since 2G/3G to 4G/5G and beyond. This is because it is impossible to realize the true propagation fading with only simulation. After the installation of base station, there is a compulsory task to test the assumed performance using drive test. If it is not acceptable, the most common adjustment is to tilt the angle of antenna plane in order to improve the performance of coverage areas. In general, there is no specific method to optimize the tilt angle in practice. Most engineers use their experiences to adjust the tilt angle. Therefore, the drive test is performed again and again until the results are satisfied. This causes the expensive costs for drive test and it wastes a lot of time depending on the experiences of engineers. Moreover, the adjustment of antenna tilts from many sectors at the same time is also impossible because it is too complicated beyond the experiences of engineers. As a result, this paper proposes the new method to optimize the antenna tilt angle based on only one drive test. Based on empirical analysis, the optimization can be undertaken in simulation and the results are close to the drive test. This method also provides the solution for either single sector or multiple sectors. The results indicate the success of using the proposed method.