In order to solve a series of problems such as high production cost and complex production technology of autoclaved aerated concrete wallboard in China, the paper puts forward the fabricated fiber grid ALC block wall board, and carries on the bending test to it and verifies the feasibility of the wall board in the actual project. The four-point loading method is used to test the bending resistance of two plain wall panels and two wall panels with fiber grid. By changing the splicing form and distributing fiber grid area to optimize the wall board, the influence of the corresponding optimization form on the failure form, deflection and flexural bearing capacity of the wall board is studied. The ultimate failure load is 1.5 times of the wall weight, and the larger the fiber grid area, the greater the flexural bearing capacity and the smaller the deflection, the better the flexural performance of the wall board. The wall board with two fiber grid wrapped around is selected as the optimization type of block wallboard, which meets the requirements of standard JG/T 169-2016 "General technical requirements of lightweight panel used for building partition". [ABSTRACT FROM AUTHOR]