Abstract: The research and development of the expansiom of function based on the existing single-component hydroxyl radical (OH) planar laser induced fluorescence technology (PLIF) has been carried out, i.e., the three parameters such as formaldehyde (CH₂O), heat release rate (HRR) and nitric oxide (NO) PLIF diagnostic module were established without the need of more lasers and detectors. At the same time, a co-flow jet flame burner has been developed and used to carry out the measurement to verify the established multi-parameters PLIF measurement technology. The two-dimensional distributions of OH, CH₂O, HRR and NO of the same flame in the axial section were obtained. The diagnostic system can be further widely used to measure structures of various flames and to analyze the produced mechanism of pollutant NO, as well as to provide experimental data to support the theoretical study on combustion reaction kinetic model and flame structure.