The invention provides a silicon-on-insulator radio frequency switching device and a manufacturing method thereof, comprising: forming a first oxide layer, a first single-crystal silicon layer, a second oxide layer, a second single-crystal silicon layer, The third oxide layer and the mask layer; the first opening and the second opening are formed by etching the mask layer, the third oxide layer, the second single crystal silicon layer and the second oxide layer; Epitaxial growth in the opening makes it consistent with the surface of the second single crystal silicon layer; etching mask layer, third oxide layer, second single crystal silicon layer, second oxide layer and first single crystal silicon layer are formed The first trench, the second trench and the third trench; deposit plasma oxide into the three trenches to form a shallow trench isolation structure; remove the third oxide layer and the mask layer; Body contact devices are formed on the two monocrystalline silicon layers. Compared with the prior art, the parasitic capacitance and the collection of positrons can be reduced, the floating body effect is suppressed, and the breakdown voltage is improved at the same time.