The invention discloses a kind of thin thermal insulating inner wall paint. The comprised components and their weight proportion are as follows: styrene-acrylic emulsion 28- 35%, titanium dioxide 8- 13%, fillings 10- 18%, borosilicate hollow microsphere 6- 12%, water- brone nanometer anti- pollution agent 0.5- 2%, defoaming agent 0.3- 0.5%. Said hollow microsphere is hollow white spherical powderwith thin wall, the main component is silicon dioxide and diboron trioxide, the real density is small and heat conductive coefficient is 0.04- 0.08 w/ m.k. The invention aslo discloses the preparation and construction method for said paint. It employs high pressure airless painting process for construction, the aperture of employed gunjet nozzle is 0.6- 0.8 mm, atomization pressure is 15- 18 Mpa,and when the coating layer is 0.3- 1.0 mm, the coating layer is homogeneous and tight, and the thermal insulating effect is good. The paint is especially suitable for building inner wall and ceiling painting.