The invention provides a laser crystal waveguide resonant cavity comprising a first laser crystal substrate, a second laser crystal substrate, a surface to which pump light enters and a surface from which laser is emergent, wherein the refractive indexes of the first substrate and the second substrate are gradually changed; and the refractive index at the bonding position of the first substrate and the second substrate is maximum, and the surface to which the pump light enters and the surface from which the laser is emergent are polished and then plated with high reflection dielectric films against laser working wavelength. The invention further provides a manufacturing process of the laser crystal waveguide resonant cavity, a waveguide cavity laser and a manufacturing process of the waveguide cavity laser. In the invention, host crystals with gradually changed refractive indexes are adopted as a waveguide material, thus the laser crystal waveguide resonant cavity has wider temperature bandwidth, can work under the condition of a large temperature range more effectively and is strong in universality.