Abstract: Dragon-Ⅱ is a linear induction accelerator, which can produce up to three bremsstrahlung X-ray pulses. Each X-ray pulse width is about 80 ns(FWHM), and time interval between pulses is about 500 ns. Each pulse X-ray dose is a critical parameter for Dragon-Ⅱ. Compton detector, combined with thermo luminescent dosemeter(TLD), was used to measure X-ray dose per pulse. MCNP program was used to design a Compton detector according to the characteristic of bremsstrahlung produced by Dragon-Ⅱ accelerator. Compton detector can measure multi-pulse X-ray signal and one pulse X-ray signal's integral is proportional to each pulse X-ray dose, and according to the total dose of three pulse X-ray obtained from TLD, each pulse X-ray dose can be obtained accurately.