The invention discloses a polarization-insensitive space folding laser resonator which comprises a total-reflection mirror, 4*N turning mirrors, an output mirror and a laser working medium, wherein the total-reflection mirror and the output mirror are perpendicular to an optical axis, and the centers of the total-reflection mirror and the output mirror are located on the optical axis; and the 4*Nturning mirrors are highly reflecting plane mirrors, and the centers of the 4*N turning mirrors are located on the optical axis, wherein the normal lines of 2*N turning mirrors are parallel to the meridian plane, and an included angle between the normal lines of two adjacent turning mirrors is 90 DEG; the normal lines of the rest 2*N turning mirrors are parallel to the sagittal plane, an includedangle between the normal lines of the rest two adjacent turning mirrors is also 90 DEG, and the included angles between the normal lines of the 4*N turning mirrors and the optical axis are 45 DEG; and the laser working medium is located on all folding arms perpendicular to the total-reflection mirror. The laser resonator eliminates the polarization selection phenomenon of the turning mirrors in the same plane. The polarization property of output laser is decided by the polarization selection characteristic of the total-reflection mirror. The higher the output power is, the better the beam quality is. The laser resonator can be applied to medium-power and high-power gas or solid laser devices.