Routine estimates of the turbulent fluxes of momentum, heat and trace gas flux have important significance in many meteorological, hydrological and other related studies. Combining with large-aperture scintillometer (LAS), temperature-gradient measurement system and tunable diode laser absorption spectroscopy (TDLAS), sensible heat flux and carbon dioxide (CO2) flux can be derived by iterative over a long optical path. This method has realized fast detection of heat flux in large natural areas and CO2 flux. The measured fluxes of sensible heat and carbon dioxide are compared with the results measured by a eddy-covariance (EC) instrument. The results show correlation coefficient of sensible heat flux is 0.91 and that of CO2 flux is 0.74, respectively. Experimental results show that optical measurement overcomes those limitations of traditional method, so this method is an inspiring method in heat and gas flux monitoring.