The utility model provides an IRIG-B time code generator with GPS synchronization, which comprises a GPS receiver, a singlechip, a DC B code generating circuit and a DC code to AC code conversion circuit, wherein, the DC B code generating circuit generates DC B codes and 1 kHz square signal P1K synchronous with PPS (pulse per second) signal; the DC code to AC code conversion circuit performs low-pass filtering and phase-shifting correction on square signal P1K, obtains 1 kHz sinusoidal carrier wave with the same frequency and phase with the square signal P1K, uses the DC B code to modulate the amplitude of the sinusoidal carrier wave and obtains AC B code. The utility model adopts hardware synchronous frequency dividing technology to obtain DC B code with high accuracy, and adopts the technologies of filtering wave, correcting phase position and modulating amplitude to obtain AC B code with high accuracy. The entire device with simple structure is easy to popularize and apply.