The return oil pipeline of aeroengine works in the mixed flow state of lubricating oil and air. The voidage measurement of oilgas two-phase in the pipeline is of great significance for understanding its characteristics, analysis and design of the pipeline. In this work, according to the practical state of oil return tube, an 8-electrode electrical capacitance tomography (ECT) sensor used for hightemperature operating condition was designed. With the array capacitance data from the designed ECT sensor, a voidage measurement model based on principal component regression (PCR) was established, and a new temperature compensation method was presented by calibrated capacitance value at different temperature in oil-filled full tube. The experiments were carried out, and the results showed that the presented voidage measurement model and its temperature compensation method were effective, and that the maximum absolute error of the voidage measurement was less than 10% with the temperature range of 20 ℃ ~ 180 ℃ .