Flexible pressure sensors have attracted significant attention in both academic and industrial fields. However, how to design and fabricate a flexible pressure sensor having high sensitivity and good linearity in a wide detection range is still a challenge. To address this challenge, this article proposes a flexible piezoresistive pressure sensor with a multilayer structure consisting of microstructured composite layers (MCLs), which are sandwiched by indium tin oxide-polyethylene terephthalate electrodes and encapsulated by an ultrasoft elastomer frame. The preparation of the conductive composite and the fabrication procedure of the pressure sensor are presented. Due to the point-to-point hemisphere microstructures of the multilayer composite layers, the pressure sensor can perceive pressure with a sensitivity of 7.66 kPa−1 in a range of 0–583 kPa. Besides, the proposed sensor features good linearity of 5.86% and an $R^{2}$ of 0.99. The developed pressure sensor has excellent repeatability of 500 cycles and a fast response time of 80 ms. The proposed sensor is verified by the experiments with primary applications, and the obtained results indicate it could be potentially utilized as wearable detectors.