Λ-enhanced gray molasses cooling (Λ-GMC) technique has been widely used in experiments to prepare cold atomic samples below the sub-Doppler temperature limit. To meet the experimental requirements of cavity quantum electrodynamics systems, we design and construct a wide-range, fast-tuning laser system by integrating tapered amplifiers, fiber phase modulators, etalon, injection locking amplification techniques etc. This laser system achieves a maximum tuning range of 600 MHz and a frequency tuning speed of 5 ns. Based on this laser system, loading atom in a crossed dipole trap assisted by cesium D2 line Λ-GMC cooling in the center of the optical microcavity is studied, and various factors affecting the atom loading are mainly as follows: laser duration $\tau $ , three-dimensional magnetic field $ \left( {{B_x}, {B_y}, {B_z}} \right) $ , single-photon detuning $\varDelta $ , two-photon detuning $\delta $ , ratio of cooling beam power to repumping beam power ${I_{{\text{cool}}}}/{I_{{\text{rep}}}}$ , and cooling beam power ${I_{{\text{cooling}}}}$ . The optimal parameters in this system are follows: $ \tau = 7{\text{ ms}},\; \delta = 0.2{\text{ MHz}},\; \varDelta = 5\varGamma, \;{I_{{\text{cool}}}}/{I_{{\text{rep}}}} = 3, {\text{ and }} {I_{{\text{cool}}}} = 1.2{I_{{\text{sat}}}}. $ Comparing with traditional PGC-assisted loading, the number of atoms is increased about 4 times, and the atomic temperature decreases from $ 25{\text{ μK}} $ to $ 8{\text{ μK}} $ . This experiment provides important insights for preparing ultracold atomic samples and capturing single atom arrays.