Abstract: The rapid development of ultra-short and ultra-intense laser technology has greatly advanced frontier research in physics under extreme strong-field conditions. This includes compact accelerators, high-brightness radiation sources, nonlinear strong-field quantum electrodynamics, as well as the production and detection of axion dark matter based on intense lasers. Over the past decade, Shanghai Jiao Tong University has carried out systematic theoretical, simulation and experimental research in this field, and has successively built a relativistic plasma research platform based on a single-beam hundred-terawatt-level laser and an extreme relativistic plasma research platform based on a dual-beam hundred-terawatt-level laser with high-precision spatiotemporal synchronization. In this paper, we present the layout, key parameters and characteristics of the newly commissioned dual-beam Chongming Laser-plasma Experimental Facility (CLEF), and highlight both completed and ongoing scientific activities, including the studies on laser-solid high-order harmonic generation, laser-plasma wakefield acceleration, nonlinear Compton scattering, and the production and detection of axion dark matter driven by intense lasers. The completion and operation of this facility will provide an essential supporting platform for experimental research in the field of extreme relativistic plasma physics.