Abstract: The transient heat flux is an important parameter simulated in the high temperature flowfield of the arc heater test. With respect to the harsh aerodynamic heating environment with high-level heat flux and intensive erosion, a modified transient heat flux measurement method is firstly proposed based on the hybrid heat transfer modes of heat capacity and one-dimensional semi-infinite heat transfer. Then, a novel structure of the transient heat flux sensor is designed and fabricated for the hybrid method. The sensor calibration is evaluated on the calibration system, and it is found that it has a good linear sensitivity and the proposed measurement method is favorable to its rapid-response. Finally, the on-site measurement results show that this type of heat flux sensor has a good robust and dynamical response, which can be applied under the high-level heat flux environment of the arc heater test.