Building energy saving and heat preserving method and hollow block

The invention discloses a building energy saving and heat preserving method and a hollow block. The method is characterized in that a phase-change gypsum board is additionally arranged in the surface of a building outer wall hollow concrete block toward the outside; in the daytime, the phase-change gypsum board is subjected to phase-change melting by absorbing the solar radiation energy and then adsorbs the latent heat to improve the thermal inertia of the wall, so that the traditional constant-property thermal insulation materials are replaced or partially replaced when the peak time of the indoor temperature wave is postponed, the heat insulating property of the wall is improved, the action of the external disturbance on the indoor thermal and humid environment is effectively retarded, the running time and the load of air conditioning equipment are decreased, the energy sources are effectively saved and the indoor thermal comfort of the buildings is improved; at night, the phase-change gypsum board releases heat outwards and the heat is changed from liquid to solid so as to realize regeneration. According to the building energy saving and heat preserving method and the hollow block, the structure is simple, the manufacturing is convenient and the energy-saving effect is good.