The matter can be instantaneously heated up to a high energy density state by the high power laser. When the high power laser is injected into silver spherical hohlraum, the high temperature radiation source formed in the hohlraum can drive the high velocity blast wave in the laboratory to study various astrophysical phenomena such as supernova remnants, stellar jets, etc. As the basis of laser driven blast wave experiments, the first experimental results of energy coupling and partitioning of silver spherical hohlraum with one laser entrance hole (LEH) on Shenguang Ⅲ prototype laser facility are introduced in this work. Four beams with 3.2 kJ of laser energy in a 1ns square laser pulse from the upper hemisphere are used to heat the silver spherical hohlraum targets. The silver spherical hohlraum targets are 800 μm-diameter and 650 μm-diameter LEH, and are fabricated by electroforming silver onto an acrylic mandrel. The laser coupling and partitioning to the targets are investigated by using the optical and X-ray diagnostics. The experimental results show that the radiation temperature is beyond 240 eV, the laser-to-X-ray conversion efficiency of silver hohlraum is 0.68 and the silver albedo is 0.83. With the driving of the high temperature radiation source, most of laser energy is coupled to the residual shell, and the high velocity blast wave can be generated. The laser energy not coupled to the target is lost through scattering light, emitting hot electrons and radiating X-rays. The experimental results show that the fraction of energy lost due to the scattering light is 15%, that due to emitting the total hot electrons is less than 1%, almost 30% of the laser energy is lost from the LEH by radiating the X-ray flux, almost 9% of the laser energy leaks from the spherical shell consisting of the 5.6 μm-thick Ag layer and 10 μm-thick CH layer through the X-ray radiation flux, and 45% of the laser energy is converted into the kinetic energy and internal energy of the remaining spherical shell. Therefore, more than 50% of the laser energy will be used to drive the high velocity blast wave in the subsequent experiments. After 950 ps, the silver plasma is concentrated in the center of the silver spherical hohlraum, which does not affect the injection of 1ns laser. The experiment on energy coupling and partitioning of a spherical silver hohlraum laser is carried out for the first time on Shenguang Ⅲ prototype laser facility, which lays a foundation for the subsequent experiments on laser driven blast wave.