The physicochemical properties of bio-oil obtained from pyrolysis of rape straw were studied. Main components of bio-oil were qualitatively analyzed by gas chromatography-mass spectrometry and Fourier-transform infrared spectroscopy. It was found that the main components of bio-oil were alcohols, aldehydes, phenols, esters, ketones, and acids. Two-stage condensation device was adopted to enhance the output of bio-oil to 43.53%. The storage and aging process of bio-oil was observed. Viscosity-temperature curve of aging bio-oil was fitted by Matlab programming. Change regulation of chemical compounds and functional groups before and after aging process were analyzed.