A three-dimensional integrated single-switch full-resonant boost converter was proposed based on silicon on insulator (SOI) process platform and gallium nitride (GaN) power transistors, in order to solve the problem of low power density of resonant power converters operating at high frequency. The switching frequency was 500 MHz. The main body of the converter adopted the derivative circuit structure of the traditional Class-E amplifier, i. e. parallel Class-E topology, and the gate driver adopted the single-switch resonant driving topology. The resonant inductance components in the converter were realized by the planar spiral inductor provided in the SOI process, the resonant capacitance components were realized by the Miller parasitic capacitance of the GaN power transistor, and the silicon-based chip and the GaN chip were connected by three-dimensional flip-chip technology. A detailed analysis was carried out around the design of circuit parameters, the realization of resonant components and the design of layout structure. Experimental results showed that when the input voltage was 12 V, the highest power density of the on-chip converter was 1.481W/mm², the full-load efficiency was 60%, and the highest efficiency was 89%. This design provides a new idea for realizing power converter with high power density and high integration.