The invention discloses a pyramid ring resonant cavity, which solves the technical problem that the traveling wave cavity in the prior art requires extremely precise installation angle of the cavity mirror and is not suitable for use in harsh environments. The main points of the technical solution are It includes a cavity and an active laser material arranged in the cavity, a corner cube prism and a one-way operation control device. The cavity also includes a high reflection mirror for reflecting the fundamental frequency light, a frequency modulation light output, and a fundamental frequency light reflection device. Cavity mirror, nonlinear crystal and right-angle prism, the beam emitted by the active laser material under the excitation of external pump enters the right-angle prism vertically and reflects out in parallel, and the beam enters the nonlinear crystal and enters the cavity mirror at an angle of 45 degrees and reflects Entering the one-way operation control device, the outgoing light returns to the active laser material after being reflected by the corner cube prism. Through the adjustment of the components in the cavity, the requirements for the installation accuracy of each component in the wall are reduced, so that the resonant cavity can meet the use in harsh environments.