We present a design of diffractive optical element to produce 3D optical chain along optical axis near the focus of a high numerical aperture (NA) lens by spatially modulating the phase of incoming vector beam. This optical chain can trap multiple individual particles in three dimensions at different planes near the focus. For flexibly controlling this special optical trapping system, we systematically analize the factors affecting the characteristics of the optical chain, such as different incoming vector polarization of light, the NA of the lens, and the structure of the DOE.