The deep integration of optical fiber communications and high-capacity, high-frequency wireless communications is a core technology for the future 6th Generation Mobile Communication (6G). It is crucial for establishing typical 6G scenarios such as immersive communications, ubiquitous connectivity, and integrated communications Artificial Intelligence (AI). This paper reviews mainstream technologies and solutions for optimizing the architecture and improving the spectral efficiency of fiber-wireless integrated transmission systems. It also summarizes the progress made by our team in these areas. Firstly, to meet the high-capacity needs of next-generation of immersive communications, a novel architecture for seamless "fiber-wireless-fiber" integrated transmission system is proposed using commercial Digital Coherent Optics (DCO). It marks a pioneering achievement in real-time wireless transmission at 100/200/400 GbE with photonics, achieving a maximum line rate of 2×240.558 Gbit/s. Secondly, for application scenarios requiring broad coverage and flexible deployment, the Digital Sub Carrier Multiplexing (DSCM) technology is incorporated into the optical fiber-wireless convergence access system. It results in a coherent Passive Optical Network (PON) supporting up to 32 channels of fixed broadband and 32 channels of W-band millimeter-wave wireless access. This coherent PON could reach a rate of 100 Gbit/s and is adaptable for flexible rate adjustments and future upgrades. Finally, addressing the demand for communication AI integration, a likelihood-aware Vector-Quantization (VQ) Variational Auto Encoder (VAE) is proposed based on AI technology for end-to-end optimization of fiber-wireless integrated communication systems. Without the need for terahertz power amplifiers, we successfully demonstrate the wireless transmission of Dual-Polarization (DP) terahertz signal at a net rate of 366.4 Gbit/s over 6.5 m 2×2 Multiple Input Multiple Output (MIMO) wireless link and 20 km Standard Single Mode Fiber (SSMF) link. These technologies exhibit tremendous potential for future 6G applications. Moreover, we briefly explored the possibilities for beyond 100 Gbit/s fiber-wireless integrated transmission technology, focusing on high capacity, long distance, integration and intelligentization.