We investigated a hypersonic plasma flow generated by a taper-cone-shaped plasma focus device toward astrophysical phenomena. The effects of applied magnetic field on shock velocity were observed with a streak camera. From the dependence of shock deceleration on the magnetic field distribution with comparable plasma beta, the gradient of magnetic field affects the shock deceleration. To compare the shock behavior from the numerical simulation with the experimental results, we developed a one-dimensional hybrid particle-in-cell code. The results indicated that the magnetic field distribution affected the deceleration of the shock velocity. It means that the shock behaviors generated by the taper-cone-shaped plasma focus device are comparable to the numerical simulation.