In order to realize the reliable ignition and clarify combustion control mechanism of hydroxylamine nitrate (HAN)-based electrically controlled solid propellant (ECSP), thermogravimetric-differential scanning calorimetry-mass spectrometry (TG-DSC-MS) and impedance-frequency scanning techniques have been used. The effects of thermal decomposition behavior, decomposition products, pressure and temperature on conductivity of ECSP were studied independently. The results showed that compared with the pure HAN solution, the thermal stability of ECSP was improved. The initial decomposition temperature was raised by 11 ℃, whereas the peak temperature of exothermic peak was decreased by 24 ℃ with a broader exothermic temperature range. Combining the thermal decomposition behavior of ECSP with the mass spectrometry curves of the gaseous products, it could be concluded that the thermal decomposition process of HAN-based ECSP might be divided into three steps: the thermal decomposition reaction of HAN, the interaction of the thermal decomposition products of HAN and the undecomposed HAN with polyvinyl alcohol (PVA), and the thermal decomposition of the residue components in ECSP. The electron conductivity of the ECSP was increased largely in the low frequency range (0-1000 Hz), but tended to be constant in the high frequency range (greater than 1000 Hz) as the frequency increased. With the increase of the pressure and temperature, the electron conductivity of the ECSP was increased. By raising the temperature to 150 ℃, the electron conductivity in the high frequency range was reduced by 2.92% compared with that obtained at 125 ℃.