摘要： Two problems exist in the repetition rate laser system with the cylindrical laser amplifier–its inability to offer the gain required for the injected seed in the low-energy stage of the laser system, and its failure to achieve efficient heat dissipation under high gain and high repetition rate. This paper proposes a new conceptual design of a laser amplifier with a circular-conical-frustum gain medium and corresponding configuration scheme for energy storage. Under the influence of its higher field synergy, the capacity of heat dissipation possessed by the system with a frustum gain medium can be increased by 10–25% and the average temperature at the steady state can be reduced by 2–4°C. With the amplified spherical wave, the energy extraction efficiency can be improved by 5% in the low-gain state and 15% in the high-gain state, and it can be further increased by 20% under the new configuration scheme of energy storage. Thus, it can be concluded that this new configuration of laser amplifier is more suitable than cylindrical amplifier and plays an important role in miniaturizing the laser system at high repetition rate.