A 4-dimensional (4-D) constellation construction and encryption scheme of dimension dissecting reorganization are proposed in this paper. In this scheme, the high-dimensional constellation is constructed by gradually decomposing and superimposing the low-dimensional constellation, and the mapping dimension, phase, and arrangement order of signals are scrambled to realize the encryption. This scheme uses the evolution from low dimension to high dimension to reduce the difficulty of constructing a high-dimensional constellation, and the confusion between dimensions facilitates the encryption of high-dimensional information. To verify the performance, an experiment to demonstrate the transmission of 46.7 Gb/s 4-D constellation mapping the intensity modulation/direct detection carrierless amplitude and phase on 2 km 7-core optical fiber has been successfully carried out.