To study the phenomenon of interaction between laser induced plasma hot core and normal shock wave in application of laser induced drag reduction, high-precision schlieren measurement technology was used to study and analyze the flow structure characteristics of laser induced plasma hot core under the impact of normal shock wave, and the influence law of laser energy and shock speed was obtained. The experimental results show that under the impact of the normal shock wave, the width of the hot core is firstly increased and then stabilized and decreased. The higher the incident laser energy is, the larger the width of the hot core is. The length of the hot core rapidly decreases under the impact of normal shock and then grows linearly, with a growth rate of approximately 19% of the incident shock speed. A basis for effectively enhancing the drag reduction effect and prolonging the duration in practical applications can be provided by the conclusions. The relevant methods and results also have a good reference value for the study of laser plasma active flow control.