The invention relates to an underground oil/gas perforation device and an underground oil/gas perforation method belonging to the field of petroleum production, and especially relates to a composite perforation device and perforation method for underground oil/gas electro-hydraulic fracturing, which uses the electro-hydraulic effect. The perforation device and perforation method provided by the invention aim to solve the problem in the prior art that the perforation bonding blocks perforated cracks because the underground oil/gas perforation charge technology is applied to rocks, thereby improving the production capacities of oil/gas wells. The perforation device comprises an aboveground delay synchronous controlmodule, a composite electro-hydraulic fracturing perforating gun module, an underground pressure-proof and heat-absorption module, a communication cable and a bearing structure, wherein the aboveground delay synchronous control module comprises a man-machine interactive control module and a technical delay circuit module; the composite electro-hydraulic fracturing perforating gun module comprisesan electro-hydraulic fracturing device and common perforating devices, and the common perforating devices comprise a perforating gun and a pressure sensor; the aboveground delay synchronous control module and the composite electro-hydraulic fracturing perforating gun module are connected by the communication cable. The perforation device and perforation method provided by the invention are applied to the field of petroleum production to solve the problems of underground oil/gas perforation blocking, and the like.