The work aims to improve the precision machining efficiency and surface quality of single-crystal SiC, a lapping- polishing method combining magnetically controlled abrasive orientation and the solid-state Fenton reaction was proposed, and a new type of lapping-polishing plate was developed and lapping-polishing performance experimental research was carried out. A magnetic field controlled the chain structure formed by magnetic particles to promote abrasives’ directional distribution to prepare the lapping-polishing plate. The solid-state Fenton reaction between the magnetic particles and H2O2 was used to generate hydroxyl radicals (.OH), and then the single-crystal SiC was oxidized to generate a silicon dioxide oxide layer with low bonding force and low hardness on its surface. The oxide layer was removed by a directionally distributed abrasive movement to achieve high-efficiency and high-quality surface lapping-polishing. The effects of magnetic field strength, abrasive orientation, solid-state Fenton reaction and their synergistic effects on the lapping-polishing performance of single-crystal SiC were studied. The experimental results showed that the surface roughness of the C-face of SiC decreased from Ra 100 nm to Ra 1.19 nm, and the material removal rate reached 33.71 nm/min when the magnetic field intensity was 100 mT and the lapping-polishing time was 60 minutes. The material removal rate of the C-face and the Si-face of SiC was increased by 60.23% and 111.19%, respectively. It was increased by 78.5% and 100.09% for the simple abrasive orientation effect and the solid-state reaction effect, respectively. Their synergy could make the material removal rate increased by 100% and 144.55%, respectively, and the surface roughness Ra decreased by 345.83% and 118.78%, respectively. The new lapping-polishing plate combines the chemical action of the solid-state Fenton reaction and the mechanical removal of the abrasive orientation, improving the material removal rate and obtaining a better lapping-polishing surface quality. It is expected to be better used in the fine lapping and polishing stages of single-crystal SiC.