The invention constructs a new gene-auto-excision binary system for biological safety control of exogenous gene in a sexual reproduction plant. The use of a transcription system as a molecular switch to control a recombinase deletion system, on one hand, keeps a recombinase gene positioned between recombinase identification loci silenced in sexual generations of a plant and realizes the stable inheritance of an exogenous gene transferred by a 'GM-gene-deletor' technique in sexual generations of a plant; on the other hand, the hybridizing of parent plants carrying an effector element and an activator element respectively closes two matched elements in the transcription system. Thus, the activity of a transcription activator is demonstrated and the deletion of the exogenous gene is realizedby promoting the expression of the recombinase by a plant tissue specific promoter to obtain a safe transgenic plant; and the biological safety hazard problem the exogenous gene may brings is solved.