Although organic-inorganic halide perovskites continue to generate considerable interest with the high potential to be widely applied in a variety of optoelectronic devices, there are some critical obstacles to practical applications such as the toxicity of lead, the relatively low field effect mobility and the strong hysteresis during operation. Here we develop a universal approach to significantly improve mobility and operational stability, and reduce the hysteresis of perovskite-based transistors simultaneously through coupling low-dimensional lead-free perovskite material (C₆H₅C₂H₄NH₃)₂SnI₄ (hereafter abbreviated as (PEA)₂SnI₄) with embedded conjugated polymers wrapped semiconducting carbon nanotubes (semi-CNTs). In the (PEA)₂SnI₄/semi-CNTs hybrid systems, semi-CNTs can contribute as smooth tracks for carriers to transport with less scattering and trapping of perovskite grain boundaries. We also demonstrate the extraordinary performance of (PEA)₂SnI₄/semi-CNTs hybrid phototransistors with ultrahigh photoresponsitivity and photosensitivity, which is found to be on a par with the best devices available to date.