Abstract:A portable test system based on PCI bus and virtual instrument technology was proposed to solve the problems of existing missile test equipment, such as large size, complex structure, difficult maintenance and long test time. On the basis of analyzing the working principle of electro-hydraulic servomechanism, its mathematical model was deduced and established. According to the dynamic testing requirements of the servo mechanism, the hardware design and selection of the test system were completed. According to the principle of "modularization, standardization and miniaturization", the industrial computer was used to control the PCI-1742U multi-function data acquisition card to realize the signal excitation and acquisition during the test process. Based on Visual Studio software development platform, the dynamic test software was compiled to realize the functions of excitation signal parameter setting, data acquisition, signal processing and data management in the test process. Finally, the influence of sampling frequency on the test results was analyzed through simulation test experiments based on sine correlation analysis and chirp signal test method.