Abstract: For the purpose of simplifying the cavity structure,enhancing the stability especially on the hot stability,enlarging the basic mode volume,improving the beam quality of the high power lasers,a right angle cone mirror laser cavity with a right-angle-cone mirror as the totally reflecting mirror and a parallel flat partially reflecting mirror as the output mirror is introduced.The results of the experiments show that when the misalignment angle of the cone mirror turns to 37.2′,the decrease of the single-pulse output energy of the plane-cone folded cavity laser is less than 5% and the near-field beam patterns have little change;the analytical results of the mode instrument show that the near-field beam intensity distribution of the plane-cone mirror folded cavity laser is uniform.The right-angle-cone mirror folded cavity has the great advantage in the anti-misalignment stability.With the simple structure,it is easy to install and adjust,especially apply to the high power laser system in a bad condition.