Abstract: In order to achieve low-threshold optofluidic fluorescence resonant energy transfer(FRET) laser, based on Fabry-Perot (F-P) microcavity with high quality factor and stability, the generation of optofluidic FRET laser in two types of F-P resonator was studied by using indirect pumping method. Firstly, donor molecules were pumped directly, and then, the excited energies of donor molecules were transferred to acceptor molecules through FRET to realize the indirect optical pumping of the acceptor. Experimental results show that the low energy density threshold of laser pump is 0.48μJ/mm² in F-P optofluidic cavity. The results indicate that the detection of low concentration substance can be realized by FRET laser generation in terms of laser detection.