Microfluidic systems based on laser induced fluorescence (LIF) detection technology have been widely used in the field of biochemistry detection. Aiming at the problem of weak fluorescence intensity induced by a few detection samples in the microfluidic system, a microfluidic chip integrating a microlens array (MLA) is designed and fabricated to improve the intensity of the detected fluorescence. An 8×8 photoresist MLA mold with the diameter variation coefficient of 0.36% is obtained by the hot melt technology. Then, a cover plate integrating a polydimethylsiloxane MLA is produced by the soft-lithography technology, and the focal length uniformity error is 7%. Afterwards, a micro-channel substrate is made. The substrate and the cover plate are packaged by the oxygen plasma bonding technology. Finally, the fluorescence intensity of the chip is detected by a fluorescence microscope, and the chip is injected by fluorescein isothiocyanate fluorescent dye solution with concentration of 10 μmol·L-1. The result shows that the fluorescence intensity with the microlens is improved about 2.2 times as much as the fluorescence intensity without the microlens.