According to the demand of vector analysis of communication signals, and the solution of advanced foreign instruments, the vector signal analysis function is developed in the high performance signal analyzer. First the input signal is received by super heterodyne conversion and AD sampling, and then high speed digital down conversion and integer ratio decimation are completed in FPGA, finally, the application software performs high-precision resampling, time-domain filter correction, transient analysis and feed-forward digital demodulation, and realizes multi-domain test and synchronous display by way of multistage configurations. The experimental results show that the vector signal analysis based on this scheme is superior in function, flexible in configuration and rich in test results.