The Circular Electron–Positron Collider (CEPC), designed to operate at center-of-mass energies up to 360 GeV, aims to enable precision studies of the Higgs boson and searches for physics beyond the Standard Model. Its silicon tracker, with an active area of approximately 100 m², is designed to provide high-precision charged-particle tracking over a wide momentum range from below 1 GeV to above 100 GeV, supporting both isolated high-momentum tracks and dense jet reconstruction, with a target momentum resolution at the 10⁻³ level. In addition, it will serve as a precision time-of-flight system with a single-layer timing resolution of about 50 ps. This talk presents the development of a 4D tracking system based on advanced semiconductor timing detectors, aiming at picosecond-level timing resolution and micrometer-level spatial resolution for next-generation high-energy physics experiments. The R&D focuses on low-gain avalanche detectors (LGADs), targeting large-area semiconductor sensors achieving better than 40 ps timing resolution and ~10 μm spatial resolution. In parallel, a dedicated fast-timing readout ASIC (LATRIC) is being developed, featuring low power consumption, high precision, and large-scale channel integration. Recent progress on silicon-based LGADs, SiC-based fast timing detectors, and the LATRIC ASIC will be presented, together with prospects for their application in CEPC and other future experiments.