A double-sided capacitor, comprising: an intermediate insulating layer disposed between a first semiconductor layer and a second semiconductor layer; the first semiconductor layer provided with a first trench and a second trench, wherein the first trench and the second trench are downward from an upper surface of the first semiconductor layer, a depth of the first trench is less than a thickness of the first semiconductor layer, and the second trench penetrates through the first semiconductor layer and the intermediate insulating layer, and reaches down to the second semiconductor layer; the second semiconductor layer provided with a third trench and a fourth trench, wherein the third trench and the fourth trench are upward from a lower surface of the second semiconductor layer, a depth of the third trench is less than a thickness of the second semiconductor layer, the fourth trench penetrates through the second semiconductor layer and the intermediate insulating layer, and reaches down to the first semiconductor layer; wherein any two of the first trench, the second trench, the third trench, and the fourth trench are not communicated; a first electrode layer disposed above the first semiconductor layer, in the first trench, and in the second trench; a first insulating layer disposed between the first electrode layer and the first semiconductor layer to isolate the first electrode layer in the first trench and in the second trench from the first semiconductor layer, and broken at a bottom of the second trench to electrically connect the first electrode layer to the second semiconductor layer; a second electrode layer disposed below the second semiconductor layer, in the third trench, and in the fourth trench; and a second insulating layer disposed between the second electrode layer and the second semiconductor layer to isolate the second electrode layer in the third trench and in the fourth trench from the second semiconductor layer, and broken at a bottom of the fourth trench to electrically connect the second electrode layer to the first semiconductor layer; wherein the first semiconductor layer, the intermediate insulating layer, and the second semiconductor layer are stacked from top to bottom in vertical direction normal to their main surfaces to form a SOI substrate, materials of the first semiconductor layer and the second semiconductor layer are monocrystalline silicon with resistivity of 1mΩ·cm, materials of middle insulating layer are silicon dioxide. an intermediate insulating layer disposed between a first semiconductor layer and a second semiconductor layer; the first semiconductor layer provided with a first trench and a second trench, wherein the first trench and the second trench are downward from an upper surface of the first semiconductor layer, a depth of the first trench is less than a thickness of the first semiconductor layer, and the second trench penetrates through the first semiconductor layer and the intermediate insulating layer, and reaches down to the second semiconductor layer; the second semiconductor layer provided with a third trench and a fourth trench, wherein the third trench and the fourth trench are upward from a lower surface of the second semiconductor layer, a depth of the third trench is less than a thickness of the second semiconductor layer, the fourth trench penetrates through the second semiconductor layer and the intermediate insulating layer, and reaches down to the first semiconductor layer; wherein any two of the first trench, the second trench, the third trench, and the fourth trench are not communicated; a first electrode layer disposed above the first semiconductor layer, in the first trench, and in the second trench; a first insulating layer disposed between the first electrode layer and the first semiconductor layer to isolate the first electrode layer in the first trench and in the second trench from the first semiconductor layer, and broken at a bottom of the second trench to electrically connect the first electrode layer to the second semiconductor layer; a second electrode layer disposed below the second semiconductor layer, in the third trench, and in the fourth trench; and a second insulating layer disposed between the second electrode layer and the second semiconductor layer to isolate the second electrode layer in the third trench and in the fourth trench from the second semiconductor layer, and broken at a bottom of the fourth trench to electrically connect the second electrode layer to the first semiconductor layer; wherein the first semiconductor layer, the intermediate insulating layer, and the second semiconductor layer are stacked from top to bottom in vertical direction normal to their main surfaces to form a SOI substrate, materials of the first semiconductor layer and the second semiconductor layer are monocrystalline silicon with resistivity of 1mΩ·cm, materials of middle insulating layer are silicon dioxide.