Spatial variations in the refractive index of the biological specimen introduce optical aberrations that degrade image quality. In confocal microscopy this is a serious limitation when imaging penetrates into thick biological specimens, in particular for in vivo tissue imaging. Adaptive optics (AO) enable mirror deformation to compensate the aberration by rapid response deformable mirror. In confocal microscopy, it can correct the aberrations, observe deep tissue activity, perform in vivo tissue imaging, measure and restore the optimum resolution. This review discusses the origins and characteristics of aberrations in confocal microscopy. The correction schemes by using adaptive optics in confocal microscopy and the research progress are discussed. Wavefront sensor, aberration measurement and aberration correction devices of adaptive optics in confocal microscope are discussed. The trends of adaptive optics in confocal microscopy are also reviewed.