To address the causes of suspended matter in mine water and the issue of suspended matter exceeding discharge standards at a certain gold mine, this study investigated the formation mechanism of suspended matter and evaluated treatment technologies. After systematically analyzing and verifying the suspended matter formation mechanism, experimental studies were condueted on the removal efficieney of suspended matter using the magnetie coagulation-sedimentation method. The results show that the suspended matter in mine water primarily forms due to the transitionfrom a reducing environment underground to an oxidizing environment at the surface, where Fe2+ is gradually oxidized by oxygen into Fe3+, which subsequently reacts with hydroxyl ions to form ferric hydroxide Fe(OH);. In single-coagulant dosing tests, PFS exhibited better coagulation performance than PAC and PAS, and anionic PAM performed better than cationic or nonionic PAM. Combined use of coagulants was more effective than single-agent dosing. The optimal removal efficiency (up to 97.06 %) was achieved with a combined dosage of 10 mg/. PFS + 2 mg/T anionic PAM. The addition of magnetic powder significantly shortened the sedimentation time compared to conventional coagulation-sedimentation, indicating that the magnetic coagulation-sedimentation process is a promising solution to the suspended matter problem in mine water at this gold mine.