The present invention provides a ray detection method and a device, a detector assembly and a ray detector, relating to the field of radiation imaging. The ray detection method provided by the invention comprises: obtaining basic detection data of each transfer layer in the detector assembly, the detector assembly consisting of a plurality of transfer layers in a multilayer arrangement, each transfer layer being configured to detect energy in a preset detection range; and obtaining ray detection data of a preset detection level on the basis of the combination of the basic detection data of the plurality of transfer layers. According to the ray detection method provided by the invention, on the basis of the basic detection date of the plurality of transfer layers, the ray detection data of the preset detection level is acquired according to the requirement of the detection level and the basic detection data of the transfer layers in accord with the preset detection level, therefore the energies of different energy levels may be flexibly detected according to the requirement of detection.