The invention discloses a testing device of gunpowder combustion characteristics in vacuum, which mainly comprises a combustion chamber, a vacuum pump, an electric heater, a thermoelectric couple, a high speed camera and a data acquisition and processing system; wherein, the vacuum pump provides vacuum environment for the combustion chamber; by controlling the heating current and the heating time of the electric heater, different ignition isoperibols can be provided for tested gunpowder samples in the combustion chamber; and the data acquisition and processing system collects the test data generated by the thermoelectric couple and the gunpowder combustion images shot by the high speed camera when the tested gunpowder samples combust, and finally obtains the combustion characteristics of the tested gunpowder samples through corresponding processing and calculation. The invention not only can be used for testing the parameters such as combustion speed, combustion surface temperature and combustion heat and the like of the gunpowder in vacuum, but also can be used for the generation and collection of the combustion products of the gunpowder under different vacuum conditions. The invention has the overriding advantages of high integration level, obtaining various parameters by one testing and low testing expenses.