The utility model provides a prefabricated light partition wall board, the partition plate is provided with tenon and joggle recess, the partition plate is built a concrete placement by the light and is formed, the inside reinforcing bar net of having buried underground of partition plate, the parcel all around of partition plate has alkali resistant glass fibre net cloth to set up film mortar layer in its outside, the left end face of partition plate is equipped with the tenon along length direction, and the right -hand member face is equipped with the joggle recess along length direction, the shape of tenon and joggle recess cooperatees completely, when the tenon of partition plate and the joggle groove connection of another partition plate, be provided with close adhesive layer at its junction, still opened on the partition plate and buried wiring cable recess. This prefabricated light partition wall board, have bulk strength height, density low, keep warm and thermal -insulatedly go with fire behavior, the seam of wallboard is more closely knit, sound insulation property advantage such as better can improve comprehensive benefit such as heat preservation, fire prevention, sound insulation, environmental protection.