The transfer path analysis（TPA）of small airborne equipment is faced with many problems，such as the complexity of working load identification and difficulty of vibration transfer path description. According to the coupling characteristics of the equipment system，the finite load nodes are used to represent the distributed dynamic load area，and the equivalent load of path point is reconstructed by using the load inversion technique based on the transfer relation matrix. The infinite transfer paths are simplified in the form of finite paths，and the virtual transfer path analysis（VTPA）model is constructed. Taking the fuel pump regulator as an example，synthesis results of the four VTPA models are compared with the forced response analysis results，and the transmissibility-based single-body transfer path analysis（TB-STPA）model with the best synthesis results is selected for path contribution analysis. The result shows that the path direction perpendicular to the installation surface has the greatest impact on the target positions，responses. Adding an auxiliary support mechanism can significantly reduce the response of the electrical socket，which verifies the effectiveness of TB-STPA method.