High-temperature thermal protective materials will be strongly scoured by high-temperature and high-speed airflow during service. Due to the Laval structure of the JP5000 spray gun, fuel and oxygen are mixed, burned and accelerated in the spray gun, and high temperature and supersonic airflow can be reached at the outlet of the spray gun. Therefore, JP5000 spray gun can be selected for the ablative test of high-temperature thermal protective materials. In this paper, the PIV method is used to study the velocity of free jet field and impinging jet field about the JP5000 spray gun under oxygen-enriched conditions. The relationship between the jet velocity and the gas flow rate and the oxygen-fuel ratio is analyzed. The maximum velocity at the nozzle can reach ~1200m/s. The experimental results have beneficial value for the ablative test of high-temperature thermal protective materials.