A method comprises: removing most suspending solid pollutants after a primary treatment for the sewage which is then placed into a secondary biochemical treatment section; mixing the magnetic sludge carbon carrier and a solvent to prepare a mixed solution which is then placed into the secondary biochemical treatment section synchronously with the sewage; uniformly mixing the sewage, the magnetic sludge carbon carrier and the activated sludge in a biochemical treatment construction; performing a dreg-water separation in a sedimentation tank on the mixed solution flowing out of the secondary biochemical treatment section; and recycling magnetic particles with the magnetic separation apparatus. The sewage treatment process with a magnetic sludge carbon carrier cooperated with standard upgrading and capacity improvement, which not only addresses sludge removal in sewage treatment plants, but also is cooperated with standard upgrading and capacity improvement, has advantages of saving investment cost, good sewage treatment effect, environmental friendliness etc.