Using coal gangue as raw material, high-efficiency inorganic polymer flocculant polymeric aluminum ferric calcium chloride (PAFCC) was prepared through high-temperature roasting, acid precipitation, polymerization, and maturation. The effects of PAFCC preparation conditions on turbidity, COD and UV₂₅₄ removal rate were studied by single factor experiments. The results showed that the optimum polymerization conditions of PAFCC were pH 2, polymerization temperature 60℃, polymerization time 5 h, and curing at 40℃ for 28 h. The coagulation results showed that the prepared PAFCC had excellent removal effect on turbidity, reaching 95.70%, and had a certain removal effect on COD and UV₂₅₄, and the removal rates reached 47.51% and 45.98%, respectively. The coagulation results of the refining wastewater showed that PAFCC had a good removal effect on turbidity and total phosphorus, while it had a certain removal effect on COD and ammonia nitrogen, and the effect was significantly better than traditional PAC.