The invention relates to the field of science and technology of neutron scattering, in particular to a rear-end rough collimator support for neutron scattering and an installation and debugging method. The rear-end rough collimator support mainly comprises a fixing base, a vertical moving plate, a horizontal moving plate and an upper-end support which are installed sequentially from bottom to top,wherein the upper-end support is installed on the upper end surface of the horizontal moving plate through screws, the vertical moving plate and the horizontal moving plate are fastened through a vertical pull plate assembly, the fixing base and the vertical moving plate are connected through vertical adjusting mechanisms, and horizontal adjusting mechanisms are installed on the vertical moving plate and the horizontal moving plate. The three-dimensional independent adjustment capability is obtained through the independent horizontal adjusting mechanisms and vertical adjusting mechanisms, andthe installation verticality can be adjusted through the vertical pull plate assembly. The rear-end rough collimator support is simple in structure and convenient to manufacture and install and has the shape identical to the vertical projection of a rear-end rough collimator, all that is required for installation adjustment is the space under the rough collimator of the support, and small space is occupied on the whole.