In this article, a novel and high efficient solvent, tetra-n-Butylammonium Hydroxide (TBAH), was used for dissolution and isolation of straw cellulose from wheat straw. The composition analysis with gas chromatography (GC) and the spectroscopic characterization analysis conducted by X-Ray diffraction (XRD)/Fourier transform infrared spectroscopy (FTIR) indicated that straw cellulose can be directly dissolved and isolated by TBAH without derivatization. The investigation on the properties of straw cellulose isolation was based on the results of single factor experiments and orthogonal experiments, with optimum conditions for straw cellulose isolation being obtained as follow: reaction temperature 60°C, reaction time 40 min, concentration of TBAH 50% and ratio of TBAH to straw 10:1 (m/m). In addition, as a solvent for cellulose, TBAH could be recycled several times with high activity being retained.