Abstract: A real-time vector analysis method for detecting an optical signal with a bandwidth greater than 1 THz includes: mapping, by a time-lens focusing system, a spectrum of a signal under test to different temporal location information; obtaining, by fully broadening an ultrashort pulse by a dispersion, a time domain spectrum of the ultrashort pulse to form a chirped swept frequency source; inputting an out of the signal under test after passing through the time-lens and the chirped swept frequency source to a coherent receiver to realize an interference process and a conversion of an optical signal to an electrical signal, and recovering an intensity information and a phase information of frequency domain of the signal under test from the electrical signal by data acquisition and processing; then recovering a full-field information of time domain of the signal under test by a Fourier inverse transform.