A time-resolved two-color laser induced fluorescence method is proposed for simultaneous 2D temperature and velocity measurements for complex multi-phase flow. A temperature sensitive dye molecule is used for temperature and velocity tagging at the same time. To effectively eliminate the temperature deviation due to image misalignment, which is commonly seen at the multi-phase boundary, a one-color-camera system is proposed that can decrease the temperature deviation from 30°C-50°C to <10∘C near the two-phase flow boundary with a high contrast ratio (0.41-0.43). Considering the strong influence of the thermal diffusion and convection processes to photo luminescence images' intensities, which can lead to significant velocity calculation deviation, a physically constrained temperature tagging method is introduced. Through both a theoretical model and measurement results, the relative velocity deviation can be decreased from 77.6% to <10% by this method. This work can effectively improve the temperature and velocity measurement accuracy of a temperature sensitive particle/molecule tagging method in multi-phase flow with strong coupling of temperature and velocity.