In this study, a low-cost and easily recyclable porous green adsorbent (magnetic porous loofah biochar, MPLB) was synthesized by modifying the almost zero-cost loofah biochar material with Fe3O4. The successful synthesis of the material was demonstrated by XRD, FTIR, SEM, VSM, and BET. In addition, the material exhibits outstanding magnetic separation performance (40.01 umg/g) allowing for rapid recovery within just 90 s. The adsorption process of phenol on MPLB was found to be spontaneous and endothermic. The experimental data fit exceptionally well with the pseudo-second-order kinetic model and Langmuir model (R2 > 0.99), indicating that the dominant adsorption mechanisms involved monolayer adsorption and chemisorption. These interactions were attributed to host–guest interaction, π–π conjugation, hydrogen bonding, and pore filling. The maximum adsorption capacity calculated using the Langmuir model at 298 K is 39.4 mg/g. Importantly, even after undergoing seven cycles of recycling, MPLB retained 78% of its initial adsorption capacity. In simulated experiments employing MPLB for phenol removal in actual wastewater, an impressive removal rate of 96.4% was achieved. In conclusion, MPLB exhibits significant potential as an effective adsorbent for phenol removal in wastewater.