The invention particularly relates to a bidirectional silicon controlled rectifier electro static discharge protection structure and an SOI structure. A first N-type doped region, a P-type doped region, and a second N-type doped region are disposed in a P substrate. A first P-type heavily doped region, a first N-type heavily doped region, and a second N-type heavily doped region are disposed in the first N-type doped region, and the second N-type heavily doped region is located at a junction of the first N-type doped region and the P-type doped region. A third N-type heavily doped region, a fourth N-type heavily doped region, and a second P-type heavily doped region are disposed successively from left to right in the second N-type doped region. The third N-type heavily doped region is located at a junction of the P-type doped region and the second N-type doped region. A gate oxide layer covers the surface of the P-type doped region and is located between the second N-type heavily dopedregion and the third N-type heavily doped region. One end of a first extraction electrode is connected with the first P-type heavily doped region and the first N-type heavily doped region. One end ofa second extraction electrode is connected with the four N-type heavily doped region and the second P-type heavily doped region.