Photophysical and photochemical reactions of air pollutants induced by sunlight radiation, particularly volatile organic contaminants (VOCs), have serious damaging effects on atmospheric environment. Via femtosecond pump-probe technique and photoelectron imaging detection technology, these photophysical and photochemical reactions in the femtosecond time scale and molecular space scale aretracked. Detailed dynamics are obtained for understanding, which are significant for further protection of the atmospheric environment. Combining with the results of nearly three years in the direction, the research progresses of this direction are summarized. The doublesided photoelectron imaging setup and experimental platform for these measurements are described. Several recent experimental results are introduced: ultrafast relaxation dynamics of the excited states of ethylbenzene; ultrafast competing intersystem crossing and internal conversion in the S2 state of o-xylene; photoisomerization dynamics of furan; multiphoton dissociation dynamics of Freon 113.