The experimental modal analysis system was introduced based on independent development software and NI hardware. The independent development software included the digital signal sampling and analyzing system（VTCL_DSP）, experimental modal analysis system (VTCL_MDT) and the NI hardware included the NI—USB9215A signal collector and a three-dimensional acceleration sensor were used in the research. The concept of measurement point response vector was given. Timing acquisition mode and variable time based on technology were adopted by the system to get the response signals and impact forces in the trigger process. A testing method of single-input and multiple-outputs has been applied in the experimental model research to get the complete mode shapes. The advantages of the method were discussed. Two application examples were also introduced: a modal analysis for power-train and a modal analysis for body-in-white. The results showed that the system has the characters of high accuracy and high stability. 