Abstract: The electron energy distribution of diode was calculated using current and voltage. Moreover, the characteristics of X-ray spectrum in parallel diodes environment were calculated using Monte Carlo simulation model. The dose distribution of X-ray of four parallel diodes environment was calculated using numerical integral method. In the model, the small cells, which were divided by diodes, were used as radiation source. The results indicate that the X-ray fluence in the position from the target 5 cm is 3.55 mJ/cm². The energy of photons with less than 120 keV in the X-ray spectrum is less than 81.84% of the total energy. The average photon energy of the X-ray spectrum is 62.18 keV, and the diode electron beams conversion efficiency is 0.30%. In the area of 2700 cm², the dose uniformities of axial and diagonal orientation are 3.20 and 6.31 separately, and in the area of 2 000 cm², the values are less than 2.