According to the conserration of flux on the zonal boundary, a zonal boundary scheme adapted to numerical simulation of hypersonic flowfield is derived for patched grid system. Based on this work, a multizonal numerical algorithm is developed for 2D/3D supersonic and hypersonic viscous complicated flowfield. Using this algorithm, the hypersonic blunt biconic viscous flowfield is numerically simulated with the angle of attack of 0^。and 4^。.