•We applied ionic liquid in the wheat straw pulping process, and its related parameters were investigated in this paper.•Single factor and orthogonal experimental methods were used to optimize the parameters of pulping process.•Pulp obtained by ionic liquid cooking had better properties than that from a standard chemical pulping process.•The ionic liquid solvent can be reused, and the recovery rate was more than 93.16%.The chloride-based 1-butyl-3-methylimidazolium ionic liquid was applied in the wheat straw pulping process, and its related parameters were investigated in this paper. Single factor and orthogonal experimental methods were used to optimize the parameters of pulping process. The results showed that the optimum pulping parameters of ionic liquid for wheat straw cooking were: cooking temperature 100 °C, cooking time 60 min and the mass ratio of wheat straw to ionic liquid 1:9 at normal atmospheric pressure. Under these conditions, the pulp yield was up to 85%. According to the physical properties of the handsheets prepared at an amplified scale, pulp obtained by ionic liquid cooking had better properties than that from a standard chemical pulping process. Moreover, the ionic liquid solvent can be reused, and the recovery rate was more than 93.16%.