Abstract: According to the structure characteristics of optical fiber multi-strand cluster carbon fiber composite conductor, the strain clamp was developed by hydraulic connection method, and the factors affecting the grip strength of the strain clamp and optical transmission performance of optical fiber were studied.In the structural design, the steel anchor of the strain clamp has optical fiber channel, and the composite core liner adopts porous structure design, which has the outstanding advantages of uniform force, large grip force and optical fiber protection.It is found that the crimping length, hydraulic pressure, structure size and lap length have important effects on the grip strength and optical fiber transmission performance of the strain clamp.By optimizing the structure and crimping parameters, the strain clamp can be effectively connected with the conductor, It has high grip strength and ensures optical transmission of the optical fiber implanted in the composite core.This is of great significance to the application of the optical fiber multi-strand cluster type carbon fiber composite core conductor.