Polyethylene pipes are widely used in critical fields such as energy transmission and water supply and drainage. Accurate detection of their locations is of great significance for ensuring urban safety. In view of the problems of noise sensitivity and inaccurate time delay calculation in existing pipeline location technologies, this paper proposes an elastic wave imaging location method based on joint denoising and mutual information time delay. Firstly, an experimental platform is built and the signals received by the geophones are collected. Secondly, the signals are denoised by using the ensemble empirical mode decomposition combined with the wavelet threshold algorithm. Then, the time delay of the signals is calculated by the mutual information function method, and the pipeline location is determined by superimposing the data of multiple survey lines. Finally, the feasibility of the method is verified by COMSOL simulation, and field tests are conducted on PE pipes buried at depths of 0.5 and 1 m. The experimental results show that the average positioning errors of the pipelines obtained by the method in this paper are 0.042 and 0.085 m, respectively, which are reduced by 0.058 and 0.820 m compared with those without denoising. Compared with the cross-correlation function method and the time-domain superposition method, the average positioning errors of the method in this paper are reduced by 0.067 and 0.063 m at a depth of 0.5 m, and by 0.222 and 0.057 m at a depth of 1 m, respectively. The research results show that this method significantly improves the positioning accuracy of pipelines and has important engineering application value for the detection of buried PE pipes in complex environments.