The utility model provides a rock core holder, be equipped with the glass observation window on the outer peripheral face of holder barrel, be equipped with left plunger and right plunger in the inside cavity of holder barrel, be equipped with the rock core thin slice on the thin slice carrier, the common cover of relative one end of left side plunger and right plunger is equipped with a transparent gum cover, the threaded cover of other end suit of right side plunger, thread bush and screw thread mouth threaded connection, be equipped with confined pressure inlet and outlet valve on the holder barrel, be equipped with a pipeline in left side plunger and the right plunger respectively, the holder barrel is worn out to the pipeline, be equipped with hydrodynamic groove on the terminal surface of left plunger and right plunger and the contact of thin slice carrier. The utility model provides circular shape thin slice carrier has been adopted to replaced the cover glass with transparent adhesive tape cover, under the effect of confined pressure, accomplished real sealedly, had simple easy -operating advantage, and supporting visual rock core holder simultaneously can the higher displacement pressure and test temperature of load with it, has realized the visual displacement of high temperature high pressure.