The invention provides a carrier 
assembly carrying a 
gene element combination, a recipient 
cell library, a preparation and 
screening method and an application, the recipient 
cell library is formed byfusing cells and the carrier 
assembly, and the carrier 
assembly at least carries three 
gene elements, respectively a plurality of first 
gene elements encoding one or more idiotypic synNotch receptors,respectively; a second gene element carrying one or more gene loops; a third gene element encoding one or more idiotypic chimeric 
antigen receptors. Wherein, when the first 
genetic element encodes one idiotypic synNotch 
receptor, the third 
genetic element must 
encode at least three idiotypic chimeric 
antigen receptors, and when the third 
genetic element encodes one idiotypic 
chimeric antigen receptor, the first genetic element must 
encode three idiotypic synNotch receptors. The gene loop is pre-programmed, a regulatory homeopathic factor is combined with a 
transcription factor, upon activation of the synNotch 
receptor encoded by the first gene element, the 
chimeric antigen receptor encoded by the third gene element is controllably expressed.