Abstract: To accurately measure target surface heat flux under water jet impinging, a new experimental method to calculate the heat flux of a target plate was introduced, which included adding a heat adiabatic material under the target plate, measuring the target plate temperature at one-point only, and using a one-dimensional inverse heat transfer. Experimental data analysis indicates that the probability of the relative error within ±5% is 93%. Because the bottom surface of the target plate is approximated to adiabatic condition, the inverse heat transfer calculated temperature of the bottom surface is slightly higher than the measured one. It is concluded that by adding a heat adiabatic material under the target plate, the accurate results of temperature and heat flux distribution of the target plate can be obtained easily even using a single-point temperature measurement method.