This paper presents a numerical simulation of a blocked pipeline and verifies the method’s applicability using existing experimental data. Wavelet analysis analyzes pressure signals of blockage types, lengths, rates, and locations inside the horizontal pipeline. A method is obtained for rapidly calculating the blockage location, length, and rate based on pressure wave reflection and transmission principles. The average error for blockage location detection using this method is 0.36%, while the error for blockage length detection is 1.47% and for blockage rate detection is 1.24%. The reasons that affect detection accuracy are given. Additionally, the pressure signals of two unique blockage models are analyzed. Combining the calculation results of multiple blockage locations and different blockage shapes shows that this method is suitable for detecting various blockage forms. The method’s applicability is also investigated when multiple blockages exist in the piping system. It is concluded that the method can only detect the blockage at the nearest position of the valve when there are multiple blockage locations in the piping.