The invention discloses a transverse groove insulating gate bipolar transistor and a manufacturing method thereof. The transverse groove insulating gate bipolar transistor structurally comprises a P type substrate, a buried oxide layer, a drift region and a deep P type body region. A deep groove grid is arranged on one side of the drift region. A deep P type emitter region and a deep N type emitter region which are connected and extend into the drift region till a BOX layer are arranged in the deep P type body region. Emitter metal is arranged on the deep P type emitter region and the deep N type emitter region which are connected. An N type buffer layer and a P type collector region are arranged on the other side of the deep P type emitter region and the other side of the deep N type emitter region. Collector metal is arranged on the P type collector region. The semiconductor manufacturing method includes the steps of manufacturing the substrate, the buried oxide layer and an N type extension layer, forming an N type emitter, the P type body region and a P type emitter through the combination of the deep groove technology and the multi-extension and high-concentration ion multi-injection technology, forming the N type buffer layer and the P type collector region through the high-concentration ion injection technology, manufacturing a polycrystalline silicon grid through the groove grid technology, and forming electrodes through drilling and aluminum depositing.