The invention discloses a process manufacturing method of a silicon-on-insulator lateral insulated gate bipolar transistor, comprising a P-type doped semiconductor substrate, a buried oxide layer is arranged on the P-type doped semiconductor substrate, an oxide layer is provided with an N-type drift region, a field oxide layer of the silicon-on-insulator lateral insulated gate bipolar transistor belongs to a second-order field oxide layer, and a field board which is formed by a gate extending to the above of the field oxide layer is a second-order field board. The second-order field oxide layer is formed by the steps of depositing the oxide layer, etching and thermal growth. An N-type doped buffer region is formed by implanting high-energy ions for self-alignment of the second-order fieldoxide layer.