The embodiment of the invention provides a spray cooling system based on heat dissipation of a tubular laser gain medium and belongs to the technical field of laser, The system comprises a tubular laser gain medium, an inner cooling device and an outer cooling device. The inner cooling device is arranged on the inner surface of the tubular laser gain medium, and the outer cooling device is arranged on the outer surface of the tubular laser gain medium. The internal cooling device is used for heat exchanging the inner surface of the tubular laser gain medium by generating spray to realize heatdissipation of the tubular laser gain medium; The external cooling device is configured to heat exchange the outer surface of the tubular laser gain medium by generating a spray to achieve heat dissipation of the tubular laser gain medium. Thus, the heat dissipation efficiency of the tubular laser gain medium is effectively improved.