Abstract:A new type of composite slab was proposed based on the characteristics of strawboard. The profiled steel sheet strawboard composite slab was prepared by strawboard and profiled steel sheet connecting by self tapping. Experimental study on bending performance of this new composite slab was conducted. The strain changes in profiled steel sheet and strawboard was observed. The deflection of the composite floor, damage process and failure modes of the composite slab were also observed. The damage mechanism and combined effect of the slab was investigated. The ultimate flexural capacities of composite slabs were obtained. The experimental results indicate that the combination approach is reasonable, and the combination effect is good, the slab has a larger capacity, and it can be used as building floor. Through experimental study and theoretical analysis, the formula of ultimate bearing capacity and the calculation formula of deformation are put forward. The experimental results are in good agreement with the theoretical results, and the feasibility of the calculation formula is verified.