[Objectives]  To investigate the mechanism by which varroa toxic protein (VTP), found in Varroa destructor saliva, kills Apis cerana, and thereby facilitate the development of new methods for controlling V. destructor. [Methods]  A two-hybrid yeast was used to screen candidate proteins that bind to VTP after which RNAi technology and qRT-PCR were used to verify the function of the interacting protein gene and detect the expression of related genes. [Results]  Eleven candidate protein genes were identified, however, a "return experiment" revealed that the fatty acid binding protein (FABP) was the only positive protein. In order to further verify the binding of FABP and VTP in vivo, the expression of fabp in bee larvae was suppressed by an injection of dsRNA-fabp. The pupation rate of larvae injected with dsRNA-fabp was significantly higher (58%) than that of those injected with VTP alone (40%). QRT-PCR indicated that the relative expression of the Mushroom body large-type kenyon cell-specific protein 1 (mblk-1) gene and ecdysone receptor (ecr) gene in the mushroom body of larvae, changed after fabp was silenced. [Conclusion]  The VTP protein in the saliva of V. destructor may cause the death of 5th instar A. cerana larvae by binding to the FABP protein.