The work aims to study the preparation process and performance optimization of lignin/PVA foam materials. The preparation process of lignin, PVA solution mass fraction, formaldehyde and sulfuric acid were explored and optimized by the control of single variable and orthogonal experiment. The single-factor experiment results showed the technological level of lignin/PVA foam materials is optimal when the mass fraction of PVA solution was 9%, the amount of lignin was 30% (the amount proposed herein indicated the mass relative to PVA, the same below), and the amount of formaldehyde and sulfuric acid was respectively 24% and 39%. The orthogonal test results showed the preparation process of lignin/PVA foam materials was the optimal combination when the mass fraction of PVA solution was 9%, the amount of lignin was 20%, and the amount of formaldehyde and sulfuric acid was respectively 40% and 47%. According to the FTIR results, lignin and PVA underwent acetal crosslinking reaction and produced lignin /PVA foam material under the appropriate conditions, but the reaction rate was low, and the substitution reaction mainly occurred at the 5th lignin benzene ring. SEM showed that, when the amount of the single-factor lignin was 30%, the mass fraction of PVA solution was 9%, the amount of formaldehyde was 24% and the amount of sulfuric acid was 47%, without considering the influence of each factor, the prepared foam material formed regular, evenly distributed pores or a large number of pore structures. In conclusion, each single factor has a great influence on the performance of the lignin/PVA foam materials. The order of priority regarding the influence of the four factors on the performance of the foam materials was: the amount of lignin>the mass fraction of PVA solution> the amount of sulfuric acid>the amount of formaldehyde.