The invention provides a phase-change heat dissipating device and a laser. The phase-change heat dissipating device comprises a vaporizing chamber, a condensation chamber, and a heat conducting end for conducting heat generated by an object to the vaporizing chamber, wherein the heat conducting end comprises a heat absorption assembly covering the object. According to the above technical scheme, the phase-change heat dissipation device has the advantages of simple structure, high heat dissipation efficiency, uniform heat dissipation, high reliability, wide application range, etc., and can be used for dissipating heat of large-power optical components, such as laser crystals, nonlinear optical crystals or semiconductor laser chip of a large-power laser, thereby uniformly dissipating heat, improving the heat dissipation efficiency, effectively improving the light emission efficiency, light output power, beam quality and service life of the large-power laser, and achieving more stable and reliable performance. In addition, the heat dissipating device has relative simple structure, wide application range, environment-friendly energy source and actual value for scale production, and can effectively reduce the size of the large-power laser.